Merge branch 'alkuzad/gitlab-ce-namespaces_encoding_docs' into 'master'

Add information about namespace encoding to API docs

Closes #25722

See merge request !10536

25 files changed, 203 insertions, 193 deletions

diff --git a/doc/api/README.md b/doc/api/README.md
index e627b6f2ee8..d444ce94573 100644
--- a/doc/api/README.md
+++ b/doc/api/README.md
@@ -303,6 +303,17 @@ Additional pagination headers are also sent back.
 | `X-Next-Page`   | The index of the next page |
 | `X-Prev-Page`   | The index of the previous page |
 
+## Namespaced path encoding
+
+If using namespaced API calls, make sure that the `NAMESPACE/PROJECT_NAME` is
+URL-encoded.
+
+For example, `/` is represented by `%2F`:
+
+```
+/api/v4/projects/diaspora%2Fdiaspora
+```
+
 ## `id` vs `iid`
 
 When you work with the API, you may notice two similar fields in API entities:
@@ -398,7 +409,6 @@ Content-Type: application/json
 }
 ```
 
-
 ## Clients
 
 There are many unofficial GitLab API Clients for most of the popular
diff --git a/doc/api/access_requests.md b/doc/api/access_requests.md
index 96b8d654c58..21de7d18632 100644
--- a/doc/api/access_requests.md
+++ b/doc/api/access_requests.md
@@ -25,7 +25,7 @@ GET /projects/:id/access_requests
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`      | integer/string | yes | The group/project ID or path |
+| `id`      | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 
 ```bash
 curl --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v4/groups/:id/access_requests
@@ -66,7 +66,7 @@ POST /projects/:id/access_requests
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`      | integer/string | yes | The group/project ID or path |
+| `id`      | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 
 ```bash
 curl --request POST --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v4/groups/:id/access_requests
@@ -97,7 +97,7 @@ PUT /projects/:id/access_requests/:user_id/approve
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`      | integer/string | yes | The group/project ID or path |
+| `id`      | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `user_id` | integer | yes   | The user ID of the access requester |
 | `access_level` | integer | no | A valid access level (defaults: `30`, developer access level) |
 
@@ -130,7 +130,7 @@ DELETE /projects/:id/access_requests/:user_id
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`      | integer/string | yes | The group/project ID or path |
+| `id`      | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `user_id` | integer | yes   | The user ID of the access requester |
 
 ```bash
diff --git a/doc/api/award_emoji.md b/doc/api/award_emoji.md
index f57928d3c93..5f3adcc397a 100644
--- a/doc/api/award_emoji.md
+++ b/doc/api/award_emoji.md
@@ -23,7 +23,7 @@ Parameters:
 
 | Attribute      | Type    | Required | Description                                                                 |
 | ---------      | ----    | -------- | -----------                                                                 |
-| `id`           | integer | yes      | The ID of a project                                                         |
+| `id`           | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user                                                         |
 | `awardable_id` | integer | yes      | The ID (`iid` for merge requests/issues, `id` for snippets) of an awardable |
 
 ```bash
@@ -83,7 +83,7 @@ Parameters:
 
 | Attribute      | Type    | Required | Description                                                                 |
 | ---------      | ----    | -------- | -----------                                                                 |
-| `id`           | integer | yes      | The ID of a project                                                         |
+| `id`           | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `awardable_id` | integer | yes      | The ID (`iid` for merge requests/issues, `id` for snippets) of an awardable |
 | `award_id`     | integer | yes      | The ID of the award emoji                                                   |
 
@@ -126,7 +126,7 @@ Parameters:
 
 | Attribute      | Type    | Required | Description                                                                 |
 | ---------      | ----    | -------- | -----------                                                                 |
-| `id`           | integer | yes      | The ID of a project                                                         |
+| `id`           | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `awardable_id` | integer | yes      | The ID (`iid` for merge requests/issues, `id` for snippets) of an awardable |
 | `name`         | string  | yes      | The name of the emoji, without colons                                       |
 
@@ -152,7 +152,7 @@ Example Response:
   "updated_at": "2016-06-17T17:47:29.266Z",
   "awardable_id": 80,
   "awardable_type": "Issue"
-}  
+}
 ```
 
 ### Delete an award emoji
@@ -170,7 +170,7 @@ Parameters:
 
 | Attribute   | Type    | Required | Description                 |
 | ---------   | ----    | -------- | -----------                 |
-| `id`        | integer | yes      | The ID of a project         |
+| `id`        | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user  |
 | `issue_iid` | integer | yes      | The internal ID of an issue |
 | `award_id`  | integer | yes      | The ID of a award_emoji     |
 
@@ -195,7 +195,7 @@ Parameters:
 
 | Attribute   | Type    | Required | Description                 |
 | ---------   | ----    | -------- | -----------                 |
-| `id`        | integer | yes      | The ID of a project         |
+| `id`        | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `issue_iid` | integer | yes      | The internal ID of an issue |
 | `note_id`   | integer | yes      | The ID of an note           |
 
@@ -237,7 +237,7 @@ Parameters:
 
 | Attribute   | Type    | Required | Description                 |
 | ---------   | ----    | -------- | -----------                 |
-| `id`        | integer | yes      | The ID of a project         |
+| `id`        | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user  |
 | `issue_iid` | integer | yes      | The internal ID of an issue |
 | `note_id`   | integer | yes      | The ID of a note            |
 | `award_id`  | integer | yes      | The ID of the award emoji   |
@@ -277,7 +277,7 @@ Parameters:
 
 | Attribute   | Type    | Required | Description                           |
 | ---------   | ----    | -------- | -----------                           |
-| `id`        | integer | yes      | The ID of a project                   |
+| `id`        | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `issue_iid` | integer | yes      | The internal ID of an issue           |
 | `note_id`   | integer | yes      | The ID of a note                      |
 | `name`      | string  | yes      | The name of the emoji, without colons |
@@ -320,7 +320,7 @@ Parameters:
 
 | Attribute   | Type    | Required | Description                 |
 | ---------   | ----    | -------- | -----------                 |
-| `id`        | integer | yes      | The ID of a project         |
+| `id`        | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user  |
 | `issue_iid` | integer | yes      | The internal ID of an issue |
 | `note_id`   | integer | yes      | The ID of a note            |
 | `award_id`  | integer | yes      | The ID of a award_emoji     |
diff --git a/doc/api/boards.md b/doc/api/boards.md
index b2106463639..17d2be0ee16 100644
--- a/doc/api/boards.md
+++ b/doc/api/boards.md
@@ -15,7 +15,7 @@ GET /projects/:id/boards
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`   | integer  | yes    | The ID of a project |
+| `id`   | integer/string  | yes    | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 
 ```bash
 curl --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v4/projects/:id/boards
@@ -71,7 +71,7 @@ GET /projects/:id/boards/:board_id/lists
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`   | integer  | yes    | The ID of a project |
+| `id`   | integer/string  | yes    | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `board_id`   | integer  | yes    | The ID of a board |
 
 ```bash
@@ -122,7 +122,7 @@ GET /projects/:id/boards/:board_id/lists/:list_id
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`      | integer | yes   | The ID of a project |
+| `id`      | integer/string | yes   | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `board_id`   | integer  | yes    | The ID of a board |
 | `list_id`| integer | yes   | The ID of a board's list |
 
@@ -154,7 +154,7 @@ POST /projects/:id/boards/:board_id/lists
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`            | integer | yes | The ID of a project |
+| `id`            | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `board_id`   | integer  | yes    | The ID of a board |
 | `label_id`         | integer  | yes | The ID of a label |
 
@@ -186,7 +186,7 @@ PUT /projects/:id/boards/:board_id/lists/:list_id
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`            | integer | yes | The ID of a project |
+| `id`            | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `board_id`   | integer  | yes    | The ID of a board |
 | `list_id`      | integer | yes | The ID of a board's list |
 | `position`         | integer  | yes  | The position of the list |
@@ -219,7 +219,7 @@ DELETE /projects/:id/boards/:board_id/lists/:list_id
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`            | integer | yes | The ID of a project |
+| `id`            | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `board_id`   | integer  | yes    | The ID of a board |
 | `list_id`      | integer | yes | The ID of a board's list |
 
diff --git a/doc/api/branches.md b/doc/api/branches.md
index 815aabda8e3..5717215deb6 100644
--- a/doc/api/branches.md
+++ b/doc/api/branches.md
@@ -12,7 +12,7 @@ GET /projects/:id/repository/branches
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer | yes | The ID of a project |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 
 ```bash
 curl --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v4/projects/5/repository/branches
@@ -59,7 +59,7 @@ GET /projects/:id/repository/branches/:branch
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer | yes | The ID of a project |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `branch` | string | yes | The name of the branch |
 
 ```bash
@@ -109,7 +109,7 @@ curl --request PUT --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer | yes | The ID of a project |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `branch` | string | yes | The name of the branch |
 | `developers_can_push` | boolean | no | Flag if developers can push to the branch |
 | `developers_can_merge` | boolean | no | Flag if developers can merge to the branch |
@@ -157,7 +157,7 @@ curl --request PUT --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer | yes | The ID of a project |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `branch` | string | yes | The name of the branch |
 
 Example response:
@@ -195,7 +195,7 @@ POST /projects/:id/repository/branches
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`          | integer | yes | The ID of a project |
+| `id`          | integer | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `branch` | string  | yes | The name of the branch |
 | `ref`         | string  | yes | The branch name or commit SHA to create branch from |
 
@@ -238,7 +238,7 @@ DELETE /projects/:id/repository/branches/:branch
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`      | integer | yes | The ID of a project |
+| `id`      | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `branch`  | string  | yes | The name of the branch |
 
 In case of an error, an explaining message is provided.
@@ -257,7 +257,7 @@ DELETE /projects/:id/repository/merged_branches
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`      | integer | yes | The ID of a project |
+| `id`      | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 
 
 ```bash
diff --git a/doc/api/build_variables.md b/doc/api/build_variables.md
index 1c26e9b33ab..9218902e84a 100644
--- a/doc/api/build_variables.md
+++ b/doc/api/build_variables.md
@@ -10,7 +10,7 @@ GET /projects/:id/variables
 
 | Attribute | Type    | required | Description         |
 |-----------|---------|----------|---------------------|
-| `id`      | integer | yes      | The ID of a project |
+| `id`      | integer/string | yes      | The ID of a project or [urlencoded NAMESPACE/PROJECT_NAME of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 
 ```
 curl --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" "https://gitlab.example.com/api/v4/projects/1/variables"
@@ -39,7 +39,7 @@ GET /projects/:id/variables/:key
 
 | Attribute | Type    | required | Description           |
 |-----------|---------|----------|-----------------------|
-| `id`      | integer | yes      | The ID of a project   |
+| `id`      | integer/string | yes      | The ID of a project or [urlencoded NAMESPACE/PROJECT_NAME of the project](README.md#namespaced-path-encoding) owned by the authenticated user   |
 | `key`     | string  | yes      | The `key` of a variable |
 
 ```
@@ -63,7 +63,7 @@ POST /projects/:id/variables
 
 | Attribute | Type    | required | Description           |
 |-----------|---------|----------|-----------------------|
-| `id`      | integer | yes      | The ID of a project   |
+| `id`      | integer/string | yes      | The ID of a project or [urlencoded NAMESPACE/PROJECT_NAME of the project](README.md#namespaced-path-encoding) owned by the authenticated user   |
 | `key`     | string  | yes      | The `key` of a variable; must have no more than 255 characters; only `A-Z`, `a-z`, `0-9`, and `_` are allowed |
 | `value`   | string  | yes      | The `value` of a variable |
 
@@ -88,7 +88,7 @@ PUT /projects/:id/variables/:key
 
 | Attribute | Type    | required | Description             |
 |-----------|---------|----------|-------------------------|
-| `id`      | integer | yes      | The ID of a project     |
+| `id`      | integer/string | yes      | The ID of a project or [urlencoded NAMESPACE/PROJECT_NAME of the project](README.md#namespaced-path-encoding) owned by the authenticated user     |
 | `key`     | string  | yes      | The `key` of a variable   |
 | `value`   | string  | yes      | The `value` of a variable |
 
@@ -113,7 +113,7 @@ DELETE /projects/:id/variables/:key
 
 | Attribute | Type    | required | Description             |
 |-----------|---------|----------|-------------------------|
-| `id`      | integer | yes      | The ID of a project     |
+| `id`      | integer/string | yes      | The ID of a project or [urlencoded NAMESPACE/PROJECT_NAME of the project](README.md#namespaced-path-encoding) owned by the authenticated user     |
 | `key`     | string  | yes      | The `key` of a variable |
 
 ```
diff --git a/doc/api/commits.md b/doc/api/commits.md
index 24c402346b1..9cb58dd3ae9 100644
--- a/doc/api/commits.md
+++ b/doc/api/commits.md
@@ -10,7 +10,7 @@ GET /projects/:id/repository/commits
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`      | integer/string | yes | The ID of a project or NAMESPACE/PROJECT_NAME owned by the authenticated user
+| `id`      | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 | `ref_name` | string | no | The name of a repository branch or tag or if not given the default branch |
 | `since` | string | no | Only commits after or on this date will be returned in ISO 8601 format YYYY-MM-DDTHH:MM:SSZ |
 | `until` | string | no | Only commits before or on this date will be returned in ISO 8601 format YYYY-MM-DDTHH:MM:SSZ |
@@ -68,7 +68,7 @@ POST /projects/:id/repository/commits
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer/string | yes | The ID of a project or NAMESPACE/PROJECT_NAME |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
 | `branch` | string | yes | The name of a branch |
 | `commit_message` | string | yes | Commit message |
 | `actions[]` | array | yes | An array of action hashes to commit as a batch. See the next table for what attributes it can take. |
@@ -155,7 +155,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`      | integer/string | yes | The ID of a project or NAMESPACE/PROJECT_NAME owned by the authenticated user
+| `id`      | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 | `sha` | string | yes | The commit hash or name of a repository branch or tag |
 
 ```bash
@@ -203,7 +203,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`      | integer/string | yes | The ID of a project or NAMESPACE/PROJECT_NAME owned by the authenticated user
+| `id`      | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 | `sha` | string | yes | The commit hash  |
 | `branch` | string | yes | The name of the branch  |
 
@@ -245,7 +245,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`      | integer/string | yes | The ID of a project or NAMESPACE/PROJECT_NAME owned by the authenticated user
+| `id`      | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 | `sha` | string | yes | The commit hash or name of a repository branch or tag |
 
 ```bash
@@ -281,7 +281,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`      | integer/string | yes | The ID of a project or NAMESPACE/PROJECT_NAME owned by the authenticated user
+| `id`      | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 | `sha` | string | yes | The commit hash or name of a repository branch or tag |
 
 ```bash
@@ -330,7 +330,7 @@ POST /projects/:id/repository/commits/:sha/comments
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`      | integer/string | yes | The ID of a project or NAMESPACE/PROJECT_NAME owned by the authenticated user
+| `id`      | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 | `sha`       | string  | yes | The commit SHA or name of a repository branch or tag |
 | `note`      | string  | yes | The text of the comment |
 | `path`      | string  | no  | The file path relative to the repository |
@@ -375,7 +375,7 @@ GET /projects/:id/repository/commits/:sha/statuses
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`      | integer/string | yes | The ID of a project or NAMESPACE/PROJECT_NAME owned by the authenticated user
+| `id`      | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 | `sha`     | string  | yes | The commit SHA
 | `ref`     | string  | no  | The name of a repository branch or tag or, if not given, the default branch
 | `stage`   | string  | no  | Filter by [build stage](../ci/yaml/README.md#stages), e.g., `test`
@@ -449,7 +449,7 @@ POST /projects/:id/statuses/:sha
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`      | integer/string | yes | The ID of a project or NAMESPACE/PROJECT_NAME owned by the authenticated user
+| `id`      | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 | `sha`     | string  | yes   | The commit SHA
 | `state`   | string  | yes   | The state of the status. Can be one of the following: `pending`, `running`, `success`, `failed`, `canceled`
 | `ref`     | string  | no    | The `ref` (branch or tag) to which the status refers
diff --git a/doc/api/deploy_keys.md b/doc/api/deploy_keys.md
index f051f55ac3e..c3fe7f84ef2 100644
--- a/doc/api/deploy_keys.md
+++ b/doc/api/deploy_keys.md
@@ -43,7 +43,7 @@ GET /projects/:id/deploy_keys
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer | yes | The ID of the project |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 
 ```bash
 curl --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" "https://gitlab.example.com/api/v4/projects/5/deploy_keys"
@@ -82,7 +82,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`      | integer | yes | The ID of the project |
+| `id`      | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `key_id`  | integer | yes | The ID of the deploy key |
 
 ```bash
@@ -114,7 +114,7 @@ POST /projects/:id/deploy_keys
 
 | Attribute  | Type | Required | Description |
 | ---------  | ---- | -------- | ----------- |
-| `id`       | integer | yes | The ID of the project |
+| `id`       | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `title`    | string  | yes | New deploy key's title |
 | `key`      | string  | yes | New deploy key |
 | `can_push` | boolean | no  | Can deploy key push to the project's repository |
@@ -145,7 +145,7 @@ DELETE /projects/:id/deploy_keys/:key_id
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`      | integer | yes | The ID of the project |
+| `id`      | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `key_id`  | integer | yes | The ID of the deploy key |
 
 ```bash
@@ -162,7 +162,7 @@ curl --request POST --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitla
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`      | integer | yes | The ID of the project |
+| `id`      | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `key_id`  | integer | yes | The ID of the deploy key |
 
 Example response:
diff --git a/doc/api/deployments.md b/doc/api/deployments.md
index 76e18c8a9bd..0273c819614 100644
--- a/doc/api/deployments.md
+++ b/doc/api/deployments.md
@@ -10,7 +10,7 @@ GET /projects/:id/deployments
 
 | Attribute | Type    | Required | Description         |
 |-----------|---------|----------|---------------------|
-| `id`      | integer | yes      | The ID of a project |
+| `id`      | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 
 ```bash
 curl --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" "https://gitlab.example.com/api/v4/projects/1/deployments"
@@ -147,7 +147,7 @@ GET /projects/:id/deployments/:deployment_id
 
 | Attribute | Type    | Required | Description         |
 |-----------|---------|----------|---------------------|
-| `id`      | integer | yes      | The ID of a project |
+| `id`      | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `deployment_id` | integer | yes      | The ID of the deployment |
 
 ```bash
diff --git a/doc/api/enviroments.md b/doc/api/enviroments.md
index 3f0a8d989f9..49930f01945 100644
--- a/doc/api/enviroments.md
+++ b/doc/api/enviroments.md
@@ -10,7 +10,7 @@ GET /projects/:id/environments
 
 | Attribute | Type    | Required | Description           |
 | --------- | ------- | -------- | --------------------- |
-| `id`      | integer | yes      | The ID of the project |
+| `id`      | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 
 ```bash
 curl --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v4/projects/1/environments
@@ -41,7 +41,7 @@ POST /projects/:id/environment
 
 | Attribute     | Type    | Required | Description                  |
 | ------------- | ------- | -------- | ---------------------------- |
-| `id`          | integer | yes      | The ID of the project        |
+| `id`          | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user        |
 | `name`        | string  | yes      | The name of the environment  |
 | `external_url` | string  | no     | Place to link to for this environment |
 
@@ -72,7 +72,7 @@ PUT /projects/:id/environments/:environments_id
 
 | Attribute       | Type    | Required                          | Description                      |
 | --------------- | ------- | --------------------------------- | -------------------------------  |
-| `id`            | integer | yes                               | The ID of the project            |
+| `id`            | integer/string | yes                               | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user            |
 | `environment_id` | integer | yes | The ID of the environment  | The ID of the environment        |
 | `name`          | string  | no                                | The new name of the environment  |
 | `external_url`  | string  | no                                | The new external_url             |
@@ -102,7 +102,7 @@ DELETE /projects/:id/environments/:environment_id
 
 | Attribute | Type    | Required | Description           |
 | --------- | ------- | -------- | --------------------- |
-| `id` | integer | yes | The ID of the project |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `environment_id` | integer | yes | The ID of the environment |
 
 ```bash
@@ -119,7 +119,7 @@ POST /projects/:id/environments/:environment_id/stop
 
 | Attribute | Type    | Required | Description           |
 | --------- | ------- | -------- | --------------------- |
-| `id` | integer | yes | The ID of the project |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `environment_id` | integer | yes | The ID of the environment |
 
 ```bash
diff --git a/doc/api/groups.md b/doc/api/groups.md
index dfc6b80bfd9..bc61bfec9b9 100644
--- a/doc/api/groups.md
+++ b/doc/api/groups.md
@@ -53,7 +53,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer/string | yes | The ID or path of a group |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the group](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `archived` | boolean | no | Limit by archived status |
 | `visibility` | string | no | Limit by visibility `public`, `internal`, or `private` |
 | `order_by` | string | no | Return projects ordered by `id`, `name`, `path`, `created_at`, `updated_at`, or `last_activity_at` fields. Default is `created_at` |
@@ -119,7 +119,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer/string | yes | The ID or path of a group |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the group](README.md#namespaced-path-encoding) owned by the authenticated user |
 
 ```bash
 curl --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v4/groups/4
@@ -299,7 +299,7 @@ POST  /groups/:id/projects/:project_id
 
 Parameters:
 
-- `id` (required) - The ID or path of a group
+- `id` (required) - The ID or [URL-encoded path of the group](README.md#namespaced-path-encoding) owned by the authenticated user
 - `project_id` (required) - The ID or path of a project
 
 ## Update group
diff --git a/doc/api/issues.md b/doc/api/issues.md
index 54c099d4bf8..5f01fcdd396 100644
--- a/doc/api/issues.md
+++ b/doc/api/issues.md
@@ -111,7 +111,7 @@ GET /groups/:id/issues?search=issue+title+or+description
 
 | Attribute   | Type           | Required | Description                                                                                                                 |
 |-------------|----------------|----------|-----------------------------------------------------------------------------------------------------------------------------|
-| `id`        | integer        | yes      | The ID of a group                                                                                                           |
+| `id`        | integer/string | yes      | The ID or [URL-encoded path of the group](README.md#namespaced-path-encoding) owned by the authenticated user  |
 | `state`     | string         | no       | Return all issues or just those that are `opened` or `closed`                                                               |
 | `labels`    | string         | no       | Comma-separated list of label names, issues must have all labels to be returned. `No+Label` lists all issues with no labels |
 | `iids`      | Array[integer] | no       | Return only the issues having the given `iid`                                                                               |
@@ -193,7 +193,7 @@ GET /projects/:id/issues?search=issue+title+or+description
 
 | Attribute   | Type           | Required | Description                                                                                                                 |
 |-------------|----------------|----------|-----------------------------------------------------------------------------------------------------------------------------|
-| `id`        | integer        | yes      | The ID of a project                                                                                                         |
+| `id`        | integer/string        | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user      |
 | `iids`      | Array[integer] | no       | Return only the milestone having the given `iid`                                                                            |
 | `state`     | string         | no       | Return all issues or just those that are `opened` or `closed`                                                               |
 | `labels`    | string         | no       | Comma-separated list of label names, issues must have all labels to be returned. `No+Label` lists all issues with no labels |
@@ -266,7 +266,7 @@ GET /projects/:id/issues/:issue_iid
 
 | Attribute   | Type    | Required | Description                          |
 |-------------|---------|----------|--------------------------------------|
-| `id`        | integer | yes      | The ID of a project                  |
+| `id`        | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user  |
 | `issue_iid` | integer | yes      | The internal ID of a project's issue |
 
 ```bash
@@ -331,7 +331,7 @@ POST /projects/:id/issues
 
 | Attribute                                 | Type    | Required | Description  |
 |-------------------------------------------|---------|----------|--------------|
-| `id`                                      | integer | yes      | The ID of a project |
+| `id`                                      | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `title`                                   | string  | yes      | The title of an issue |
 | `description`                             | string  | no       | The description of an issue  |
 | `confidential`                            | boolean | no       | Set an issue to be confidential. Default is `false`.  |
@@ -391,7 +391,7 @@ PUT /projects/:id/issues/:issue_iid
 
 | Attribute      | Type    | Required | Description                                                                                                |
 |----------------|---------|----------|------------------------------------------------------------------------------------------------------------|
-| `id`           | integer | yes      | The ID of a project                                                                                        |
+| `id`           | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `issue_iid`    | integer | yes      | The internal ID of a project's issue                                                                       |
 | `title`        | string  | no       | The title of an issue                                                                                      |
 | `description`  | string  | no       | The description of an issue                                                                                |
@@ -450,7 +450,7 @@ DELETE /projects/:id/issues/:issue_iid
 
 | Attribute   | Type    | Required | Description                          |
 |-------------|---------|----------|--------------------------------------|
-| `id`        | integer | yes      | The ID of a project                  |
+| `id`        | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user  |
 | `issue_iid` | integer | yes      | The internal ID of a project's issue |
 
 ```bash
@@ -472,7 +472,7 @@ POST /projects/:id/issues/:issue_iid/move
 
 | Attribute       | Type    | Required | Description                          |
 |-----------------|---------|----------|--------------------------------------|
-| `id`            | integer | yes      | The ID of a project                  |
+| `id`            | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user  |
 | `issue_iid`     | integer | yes      | The internal ID of a project's issue |
 | `to_project_id` | integer | yes      | The ID of the new project            |
 
@@ -528,7 +528,7 @@ POST /projects/:id/issues/:issue_iid/subscribe
 
 | Attribute   | Type    | Required | Description                          |
 |-------------|---------|----------|--------------------------------------|
-| `id`        | integer | yes      | The ID of a project                  |
+| `id`        | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user  |
 | `issue_iid` | integer | yes      | The internal ID of a project's issue |
 
 ```bash
@@ -583,7 +583,7 @@ POST /projects/:id/issues/:issue_iid/unsubscribe
 
 | Attribute   | Type    | Required | Description                          |
 |-------------|---------|----------|--------------------------------------|
-| `id`        | integer | yes      | The ID of a project                  |
+| `id`        | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user  |
 | `issue_iid` | integer | yes      | The internal ID of a project's issue |
 
 ```bash
@@ -602,7 +602,7 @@ POST /projects/:id/issues/:issue_iid/todo
 
 | Attribute   | Type    | Required | Description                          |
 |-------------|---------|----------|--------------------------------------|
-| `id`        | integer | yes      | The ID of a project                  |
+| `id`        | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user  |
 | `issue_iid` | integer | yes      | The internal ID of a project's issue |
 
 ```bash
@@ -693,7 +693,7 @@ POST /projects/:id/issues/:issue_iid/time_estimate
 
 | Attribute   | Type    | Required | Description                              |
 |-------------|---------|----------|------------------------------------------|
-| `id`        | integer | yes      | The ID of a project                      |
+| `id`        | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user      |
 | `issue_iid` | integer | yes      | The internal ID of a project's issue     |
 | `duration`  | string  | yes      | The duration in human format. e.g: 3h30m |
 
@@ -722,7 +722,7 @@ POST /projects/:id/issues/:issue_iid/reset_time_estimate
 
 | Attribute   | Type    | Required | Description                          |
 |-------------|---------|----------|--------------------------------------|
-| `id`        | integer | yes      | The ID of a project                  |
+| `id`        | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user  |
 | `issue_iid` | integer | yes      | The internal ID of a project's issue |
 
 ```bash
@@ -750,7 +750,7 @@ POST /projects/:id/issues/:issue_iid/add_spent_time
 
 | Attribute   | Type    | Required | Description                              |
 |-------------|---------|----------|------------------------------------------|
-| `id`        | integer | yes      | The ID of a project                      |
+| `id`        | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user      |
 | `issue_iid` | integer | yes      | The internal ID of a project's issue     |
 | `duration`  | string  | yes      | The duration in human format. e.g: 3h30m |
 
@@ -779,7 +779,7 @@ POST /projects/:id/issues/:issue_iid/reset_spent_time
 
 | Attribute   | Type    | Required | Description                          |
 |-------------|---------|----------|--------------------------------------|
-| `id`        | integer | yes      | The ID of a project                  |
+| `id`        | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `issue_iid` | integer | yes      | The internal ID of a project's issue |
 
 ```bash
@@ -805,7 +805,7 @@ GET /projects/:id/issues/:issue_iid/time_stats
 
 | Attribute   | Type    | Required | Description                          |
 |-------------|---------|----------|--------------------------------------|
-| `id`        | integer | yes      | The ID of a project                  |
+| `id`        | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user  |
 | `issue_iid` | integer | yes      | The internal ID of a project's issue |
 
 ```bash
diff --git a/doc/api/jobs.md b/doc/api/jobs.md
index 7340123e09d..bea2b96c97a 100644
--- a/doc/api/jobs.md
+++ b/doc/api/jobs.md
@@ -10,7 +10,7 @@ GET /projects/:id/jobs
 
 | Attribute | Type    | Required | Description         |
 |-----------|---------|----------|---------------------|
-| `id`      | integer | yes      | The ID of a project |
+| `id`      | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `scope`   | string **or** array of strings | no | The scope of jobs to show, one or array of: `created`, `pending`, `running`, `failed`, `success`, `canceled`, `skipped`; showing all jobs if none provided |
 
 ```
@@ -125,7 +125,7 @@ GET /projects/:id/pipeline/:pipeline_id/jobs
 
 | Attribute     | Type                           | Required | Description          |
 |---------------|--------------------------------|----------|----------------------|
-| `id`          | integer                        | yes      | The ID of a project  |
+| `id`          | integer/string                        | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user  |
 | `pipeline_id` | integer                        | yes      | The ID of a pipeline |
 | `scope`       | string **or** array of strings | no       | The scope of jobs to show, one or array of: `created`, `pending`, `running`, `failed`, `success`, `canceled`, `skipped`; showing all jobs if none provided |
 
@@ -241,7 +241,7 @@ GET /projects/:id/jobs/:job_id
 
 | Attribute  | Type    | Required | Description         |
 |------------|---------|----------|---------------------|
-| `id`       | integer | yes      | The ID of a project |
+| `id`       | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `job_id` | integer | yes      | The ID of a job   |
 
 ```
@@ -309,7 +309,7 @@ GET /projects/:id/jobs/:job_id/artifacts
 
 | Attribute  | Type    | Required | Description         |
 |------------|---------|----------|---------------------|
-| `id`       | integer | yes      | The ID of a project |
+| `id`       | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `job_id` | integer | yes      | The ID of a job   |
 
 ```
@@ -340,7 +340,7 @@ Parameters
 
 | Attribute   | Type    | Required | Description               |
 |-------------|---------|----------|-------------------------- |
-| `id`        | integer | yes      | The ID of a project       |
+| `id`        | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user       |
 | `ref_name`  | string  | yes      | The ref from a repository |
 | `job`       | string  | yes      | The name of the job       |
 
@@ -369,7 +369,7 @@ GET /projects/:id/jobs/:job_id/trace
 
 | Attribute  | Type    | Required | Description         |
 |------------|---------|----------|---------------------|
-| id         | integer | yes      | The ID of a project |
+| id         | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | job_id     | integer | yes      | The ID of a job     |
 
 ```
@@ -393,7 +393,7 @@ POST /projects/:id/jobs/:job_id/cancel
 
 | Attribute  | Type    | Required | Description         |
 |------------|---------|----------|---------------------|
-| `id`       | integer | yes      | The ID of a project |
+| `id`       | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `job_id`   | integer | yes      | The ID of a job     |
 
 ```
@@ -439,7 +439,7 @@ POST /projects/:id/jobs/:job_id/retry
 
 | Attribute  | Type    | Required | Description         |
 |------------|---------|----------|---------------------|
-| `id`       | integer | yes      | The ID of a project |
+| `id`       | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `job_id`   | integer | yes      | The ID of a job     |
 
 ```
@@ -487,7 +487,7 @@ Parameters
 
 | Attribute   | Type    | Required | Description         |
 |-------------|---------|----------|---------------------|
-| `id`        | integer | yes      | The ID of a project |
+| `id`        | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `job_id`    | integer | yes      | The ID of a job     |
 
 Example of request
@@ -537,7 +537,7 @@ Parameters
 
 | Attribute   | Type    | Required | Description         |
 |-------------|---------|----------|---------------------|
-| `id`        | integer | yes      | The ID of a project |
+| `id`        | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `job_id`    | integer | yes      | The ID of a job     |
 
 Example request:
@@ -585,7 +585,7 @@ POST /projects/:id/jobs/:job_id/play
 
 | Attribute | Type    | Required | Description         |
 |-----------|---------|----------|---------------------|
-| `id`      | integer | yes      | The ID of a project |
+| `id`      | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `job_id`  | integer | yes      | The ID of a job     |
 
 ```
diff --git a/doc/api/labels.md b/doc/api/labels.md
index 839000a4f48..778348ea371 100644
--- a/doc/api/labels.md
+++ b/doc/api/labels.md
@@ -10,7 +10,7 @@ GET /projects/:id/labels
 
 | Attribute | Type    | Required | Description           |
 | --------- | ------- | -------- | --------------------- |
-| `id`      | integer | yes      | The ID of the project |
+| `id`      | integer/string    | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 
 ```bash
 curl --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v4/projects/1/labels
@@ -88,7 +88,7 @@ POST /projects/:id/labels
 
 | Attribute     | Type    | Required | Description                  |
 | ------------- | ------- | -------- | ---------------------------- |
-| `id`          | integer | yes      | The ID of the project        |
+| `id`      | integer/string    | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `name`        | string  | yes      | The name of the label        |
 | `color`       | string  | yes      | The color of the label given in 6-digit hex notation with leading '#' sign (e.g. #FFAABB) or one of the [CSS color names](https://developer.mozilla.org/en-US/docs/Web/CSS/color_value#Color_keywords) |
 | `description` | string  | no       | The description of the label |
@@ -124,7 +124,7 @@ DELETE /projects/:id/labels
 
 | Attribute | Type    | Required | Description           |
 | --------- | ------- | -------- | --------------------- |
-| `id`      | integer | yes      | The ID of the project |
+| `id`      | integer/string    | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `name`    | string  | yes      | The name of the label |
 
 ```bash
@@ -142,7 +142,7 @@ PUT /projects/:id/labels
 
 | Attribute       | Type    | Required                          | Description                      |
 | --------------- | ------- | --------------------------------- | -------------------------------  |
-| `id`            | integer | yes                               | The ID of the project            |
+| `id`      | integer/string    | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `name`          | string  | yes                               | The name of the existing label   |
 | `new_name`      | string  | yes if `color` is not provided    | The new name of the label        |
 | `color`         | string  | yes if `new_name` is not provided | The color of the label given in 6-digit hex notation with leading '#' sign (e.g. #FFAABB) or one of the [CSS color names](https://developer.mozilla.org/en-US/docs/Web/CSS/color_value#Color_keywords) |
@@ -182,7 +182,7 @@ POST /projects/:id/labels/:label_id/subscribe
 
 | Attribute  | Type              | Required | Description                          |
 | ---------- | ----------------- | -------- | ------------------------------------ |
-| `id`       | integer           | yes      | The ID of a project                  |
+| `id`      | integer/string    | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `label_id` | integer or string | yes      | The ID or title of a project's label |
 
 ```bash
@@ -217,7 +217,7 @@ POST /projects/:id/labels/:label_id/unsubscribe
 
 | Attribute  | Type              | Required | Description                          |
 | ---------- | ----------------- | -------- | ------------------------------------ |
-| `id`       | integer           | yes      | The ID of a project                  |
+| `id`      | integer/string    | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `label_id` | integer or string | yes      | The ID or title of a project's label |
 
 ```bash
diff --git a/doc/api/members.md b/doc/api/members.md
index fe46f8f84bc..3c661284f11 100644
--- a/doc/api/members.md
+++ b/doc/api/members.md
@@ -23,7 +23,7 @@ GET /projects/:id/members
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`      | integer/string | yes | The group/project ID or path |
+| `id`      | integer/string | yes | The ID or [URL-encoded path of the project or group](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `query`   | string | no     | A query string to search for members |
 
 ```bash
@@ -65,7 +65,7 @@ GET /projects/:id/members/:user_id
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`      | integer/string | yes | The group/project ID or path |
+| `id`      | integer/string | yes | The ID or [URL-encoded path of the project or group](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `user_id` | integer | yes   | The user ID of the member |
 
 ```bash
@@ -98,7 +98,7 @@ POST /projects/:id/members
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`      | integer/string  | yes | The group/project ID or path |
+| `id`      | integer/string | yes | The ID or [URL-encoded path of the project or group](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `user_id` | integer         | yes | The user ID of the new member |
 | `access_level` | integer | yes | A valid access level |
 | `expires_at` | string | no | A date string in the format YEAR-MONTH-DAY |
@@ -132,7 +132,7 @@ PUT /projects/:id/members/:user_id
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`      | integer/string | yes | The group/project ID or path |
+| `id`      | integer/string | yes | The ID or [URL-encoded path of the project or group](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `user_id` | integer | yes   | The user ID of the member |
 | `access_level` | integer | yes | A valid access level |
 | `expires_at` | string | no | A date string in the format YEAR-MONTH-DAY |
@@ -166,7 +166,7 @@ DELETE /projects/:id/members/:user_id
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id`      | integer/string | yes | The group/project ID or path |
+| `id`      | integer/string | yes | The ID or [URL-encoded path of the project or group](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `user_id` | integer | yes   | The user ID of the member |
 
 ```bash
diff --git a/doc/api/merge_requests.md b/doc/api/merge_requests.md
index 2e0545da1c4..ff956add348 100644
--- a/doc/api/merge_requests.md
+++ b/doc/api/merge_requests.md
@@ -15,7 +15,7 @@ GET /projects/:id/merge_requests?iids[]=42&iids[]=43
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `iid` (optional) - Return the request having the given `iid`
 - `state` (optional) - Return `all` requests or just those that are `merged`, `opened` or `closed`
 - `order_by` (optional) - Return requests ordered by `created_at` or `updated_at` fields. Default is `created_at`
@@ -87,7 +87,7 @@ GET /projects/:id/merge_requests/:merge_request_iid
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `merge_request_iid` (required) - The internal ID of the merge request
 
 ```json
@@ -155,7 +155,7 @@ GET /projects/:id/merge_requests/:merge_request_iid/commits
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `merge_request_iid` (required) - The internal ID of the merge request
 
 
@@ -192,7 +192,7 @@ GET /projects/:id/merge_requests/:merge_request_iid/changes
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `merge_request_iid` (required) - The internal ID of the merge request
 
 ```json
@@ -271,7 +271,7 @@ POST /projects/:id/merge_requests
 
 | Attribute              | Type    | Required | Description                                                                     |
 | ---------              | ----    | -------- | -----------                                                                     |
-| `id`                   | string  | yes      | The ID of a project                                                             |
+| `id`                   | integer/string  | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `source_branch`        | string  | yes      | The source branch                                                               |
 | `target_branch`        | string  | yes      | The target branch                                                               |
 | `title`                | string  | yes      | Title of MR                                                                     |
@@ -347,7 +347,7 @@ PUT /projects/:id/merge_requests/:merge_request_iid
 
 | Attribute              | Type    | Required | Description                                                                     |
 | ---------              | ----    | -------- | -----------                                                                     |
-| `id`                   | string  | yes      | The ID of a project                                                             |
+| `id`                   | integer/string  | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `merge_request_iid`    | integer | yes      | The ID of a merge request                                                       |
 | `target_branch`        | string  | no       | The target branch                                                               |
 | `title`                | string  | no       | Title of MR                                                                     |
@@ -422,9 +422,9 @@ Only for admins and project owners. Soft deletes the merge request in question.
 DELETE /projects/:id/merge_requests/:merge_request_iid
 ```
 
-| Attribute           | Type    | Required | Description                          |
-| ---------           | ----    | -------- | -----------                          |
-| `id`                | integer | yes      | The ID of a project                  |
+| Attribute | Type    | Required | Description                          |
+| --------- | ----    | -------- | -----------                          |
+| `id`      | integer/string  | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `merge_request_iid` | integer | yes      | The internal ID of the merge request |
 
 ```bash
@@ -450,7 +450,7 @@ PUT /projects/:id/merge_requests/:merge_request_iid/merge
 
 Parameters:
 
-- `id` (required)                           - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `merge_request_iid` (required)            - Internal ID of MR
 - `merge_commit_message` (optional)         - Custom merge commit message
 - `should_remove_source_branch` (optional)  - if `true` removes the source branch
@@ -524,7 +524,7 @@ PUT /projects/:id/merge_requests/:merge_request_iid/cancel_merge_when_pipeline_s
 ```
 Parameters:
 
-- `id` (required)                           - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `merge_request_iid` (required)            - Internal ID of MR
 
 ```json
@@ -596,7 +596,7 @@ GET /projects/:id/merge_requests/:merge_request_iid/closes_issues
 
 | Attribute           | Type    | Required | Description                          |
 | ---------           | ----    | -------- | -----------                          |
-| `id`                | integer | yes      | The ID of a project                  |
+| `id`                | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user                  |
 | `merge_request_iid` | integer | yes      | The internal ID of the merge request |
 
 ```bash
@@ -671,7 +671,7 @@ POST /projects/:id/merge_requests/:merge_request_iid/subscribe
 
 | Attribute           | Type    | Required | Description                 |
 | ---------           | ----    | -------- | -----------                 |
-| `id`                | integer | yes      | The ID of a project         |
+| `id`                | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user         |
 | `merge_request_iid` | integer | yes      | The internal ID of the merge request |
 
 ```bash
@@ -745,7 +745,7 @@ POST /projects/:id/merge_requests/:merge_request_iid/unsubscribe
 
 | Attribute           | Type    | Required | Description                          |
 | ---------           | ----    | -------- | -----------                          |
-| `id`                | integer | yes      | The ID of a project                  |
+| `id`                | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user                  |
 | `merge_request_iid` | integer | yes      | The internal ID of the merge request |
 
 ```bash
@@ -819,7 +819,7 @@ POST /projects/:id/merge_requests/:merge_request_iid/todo
 
 | Attribute           | Type    | Required | Description                          |
 | ---------           | ----    | -------- | -----------                          |
-| `id`                | integer | yes      | The ID of a project                  |
+| `id`                | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user                  |
 | `merge_request_iid` | integer | yes      | The internal ID of the merge request |
 
 ```bash
@@ -1027,7 +1027,7 @@ POST /projects/:id/merge_requests/:merge_request_iid/time_estimate
 
 | Attribute           | Type    | Required | Description                              |
 | ---------           | ----    | -------- | -----------                              |
-| `id`                | integer | yes      | The ID of a project                      |
+| `id`                | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user                      |
 | `merge_request_iid` | integer | yes      | The internal ID of the merge request     |
 | `duration`          | string  | yes      | The duration in human format. e.g: 3h30m |
 
@@ -1056,7 +1056,7 @@ POST /projects/:id/merge_requests/:merge_request_iid/reset_time_estimate
 
 | Attribute           | Type    | Required | Description                                  |
 | ---------           | ----    | -------- | -----------                                  |
-| `id`                | integer | yes      | The ID of a project                          |
+| `id`                | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user                          |
 | `merge_request_iid` | integer | yes      | The internal ID of a project's merge_request |
 
 ```bash
@@ -1084,7 +1084,7 @@ POST /projects/:id/merge_requests/:merge_request_iid/add_spent_time
 
 | Attribute           | Type    | Required | Description                              |
 | ---------           | ----    | -------- | -----------                              |
-| `id`                | integer | yes      | The ID of a project                      |
+| `id`                | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user                      |
 | `merge_request_iid` | integer | yes      | The internal ID of the merge request     |
 | `duration`          | string  | yes      | The duration in human format. e.g: 3h30m |
 
@@ -1113,7 +1113,7 @@ POST /projects/:id/merge_requests/:merge_request_iid/reset_spent_time
 
 | Attribute           | Type    | Required | Description                                  |
 | ---------           | ----    | -------- | -----------                                  |
-| `id`                | integer | yes      | The ID of a project                          |
+| `id`                | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user                          |
 | `merge_request_iid` | integer | yes      | The internal ID of a project's merge_request |
 
 ```bash
@@ -1139,7 +1139,7 @@ GET /projects/:id/merge_requests/:merge_request_iid/time_stats
 
 | Attribute           | Type    | Required | Description                          |
 | ---------           | ----    | -------- | -----------                          |
-| `id`                | integer | yes      | The ID of a project                  |
+| `id`                | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user                  |
 | `merge_request_iid` | integer | yes      | The internal ID of the merge request |
 
 ```bash
diff --git a/doc/api/milestones.md b/doc/api/milestones.md
index 3c86357a6c3..7640eeb8d00 100644
--- a/doc/api/milestones.md
+++ b/doc/api/milestones.md
@@ -17,7 +17,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer | yes | The ID of a project |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `iids` | Array[integer] | optional | Return only the milestones having the given `iids` |
 | `state` | string | optional | Return only `active` or `closed` milestones` |
 | `search` | string | optional | Return only milestones with a title or description matching the provided string |
@@ -56,8 +56,8 @@ GET /projects/:id/milestones/:milestone_id
 
 Parameters:
 
-- `id` (required) - The ID of a project
-- `milestone_id` (required) - The ID of a project milestone
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
+- `milestone_id` (required) - The ID of the project's milestone
 
 ## Create new milestone
 
@@ -69,7 +69,7 @@ POST /projects/:id/milestones
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `title` (required) - The title of an milestone
 - `description` (optional) - The description of the milestone
 - `due_date` (optional) - The due date of the milestone
@@ -85,7 +85,7 @@ PUT /projects/:id/milestones/:milestone_id
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `milestone_id` (required) - The ID of a project milestone
 - `title` (optional) - The title of a milestone
 - `description` (optional) - The description of a milestone
@@ -103,7 +103,7 @@ GET /projects/:id/milestones/:milestone_id/issues
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `milestone_id` (required) - The ID of a project milestone
 
 ## Get all merge requests assigned to a single milestone
@@ -116,5 +116,5 @@ GET /projects/:id/milestones/:milestone_id/merge_requests
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `milestone_id` (required) - The ID of a project milestone
diff --git a/doc/api/notes.md b/doc/api/notes.md
index 5e927143714..b71fea5fc9f 100644
--- a/doc/api/notes.md
+++ b/doc/api/notes.md
@@ -14,7 +14,7 @@ GET /projects/:id/issues/:issue_iid/notes
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `issue_iid` (required) - The IID of an issue
 
 ```json
@@ -68,7 +68,7 @@ GET /projects/:id/issues/:issue_iid/notes/:note_id
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `issue_iid` (required) - The IID of a project issue
 - `note_id` (required) - The ID of an issue note
 
@@ -83,7 +83,7 @@ POST /projects/:id/issues/:issue_iid/notes
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `issue_id` (required) - The IID of an issue
 - `body` (required) - The content of a note
 - `created_at` (optional) - Date time string, ISO 8601 formatted, e.g. 2016-03-11T03:45:40Z
@@ -98,7 +98,7 @@ PUT /projects/:id/issues/:issue_iid/notes/:note_id
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `issue_iid` (required) - The IID of an issue
 - `note_id` (required) - The ID of a note
 - `body` (required) - The content of a note
@@ -115,7 +115,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer | yes | The ID of a project |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `issue_iid` | integer | yes | The IID of an issue |
 | `note_id` | integer | yes | The ID of a note |
 
@@ -135,7 +135,7 @@ GET /projects/:id/snippets/:snippet_id/notes
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `snippet_id` (required) - The ID of a project snippet
 
 ### Get single snippet note
@@ -148,7 +148,7 @@ GET /projects/:id/snippets/:snippet_id/notes/:note_id
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `snippet_id` (required) - The ID of a project snippet
 - `note_id` (required) - The ID of an snippet note
 
@@ -182,7 +182,7 @@ POST /projects/:id/snippets/:snippet_id/notes
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `snippet_id` (required) - The ID of a snippet
 - `body` (required) - The content of a note
 
@@ -196,7 +196,7 @@ PUT /projects/:id/snippets/:snippet_id/notes/:note_id
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `snippet_id` (required) - The ID of a snippet
 - `note_id` (required) - The ID of a note
 - `body` (required) - The content of a note
@@ -213,7 +213,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer | yes | The ID of a project |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `snippet_id` | integer | yes | The ID of a snippet |
 | `note_id` | integer | yes | The ID of a note |
 
@@ -233,7 +233,7 @@ GET /projects/:id/merge_requests/:merge_request_iid/notes
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `merge_request_iid` (required) - The IID of a project merge request
 
 ### Get single merge request note
@@ -246,7 +246,7 @@ GET /projects/:id/merge_requests/:merge_request_iid/notes/:note_id
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `merge_request_iid` (required) - The IID of a project merge request
 - `note_id` (required) - The ID of a merge request note
 
@@ -283,7 +283,7 @@ POST /projects/:id/merge_requests/:merge_request_iid/notes
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `merge_request_iid` (required) - The IID of a merge request
 - `body` (required) - The content of a note
 
@@ -297,7 +297,7 @@ PUT /projects/:id/merge_requests/:merge_request_iid/notes/:note_id
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `merge_request_iid` (required) - The IID of a merge request
 - `note_id` (required) - The ID of a note
 - `body` (required) - The content of a note
@@ -314,7 +314,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer | yes | The ID of a project |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `merge_request_iid` | integer | yes | The IID of a merge request |
 | `note_id` | integer | yes | The ID of a note |
 
diff --git a/doc/api/pipeline_triggers.md b/doc/api/pipeline_triggers.md
index 50fc19f0e08..d639e8a0991 100644
--- a/doc/api/pipeline_triggers.md
+++ b/doc/api/pipeline_triggers.md
@@ -12,7 +12,7 @@ GET /projects/:id/triggers
 
 | Attribute | Type    | required | Description         |
 |-----------|---------|----------|---------------------|
-| `id`      | integer | yes      | The ID of a project |
+| `id`      | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 
 ```
 curl --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" "https://gitlab.example.com/api/v4/projects/1/triggers"
@@ -43,7 +43,7 @@ GET /projects/:id/triggers/:trigger_id
 
 | Attribute    | Type    | required | Description              |
 |--------------|---------|----------|--------------------------|
-| `id`         | integer | yes      | The ID of a project      |
+| `id`         | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user      |
 | `trigger_id` | integer | yes      | The trigger id           |
 
 ```
@@ -73,7 +73,7 @@ POST /projects/:id/triggers
 
 | Attribute     | Type    | required | Description              |
 |---------------|---------|----------|--------------------------|
-| `id`          | integer | yes      | The ID of a project      |
+| `id`          | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user      |
 | `description` | string  | yes      | The trigger name         |
 
 ```
@@ -103,7 +103,7 @@ PUT /projects/:id/triggers/:trigger_id
 
 | Attribute     | Type    | required | Description              |
 |---------------|---------|----------|--------------------------|
-| `id`          | integer | yes      | The ID of a project      |
+| `id`          | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user      |
 | `trigger_id`  | integer | yes      | The trigger id           |
 | `description` | string  | no       | The trigger name         |
 
@@ -134,7 +134,7 @@ POST /projects/:id/triggers/:trigger_id/take_ownership
 
 | Attribute     | Type    | required | Description              |
 |---------------|---------|----------|--------------------------|
-| `id`          | integer | yes      | The ID of a project      |
+| `id`          | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user      |
 | `trigger_id`  | integer | yes      | The trigger id           |
 
 ```
@@ -164,7 +164,7 @@ DELETE /projects/:id/triggers/:trigger_id
 
 | Attribute      | Type    | required | Description              |
 |----------------|---------|----------|--------------------------|
-| `id`           | integer | yes      | The ID of a project      |
+| `id`           | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user      |
 | `trigger_id`   | integer | yes      | The trigger id           |
 
 ```
diff --git a/doc/api/pipelines.md b/doc/api/pipelines.md
index 574a8bacb25..732ad8da4ac 100644
--- a/doc/api/pipelines.md
+++ b/doc/api/pipelines.md
@@ -10,7 +10,7 @@ GET /projects/:id/pipelines
 
 | Attribute | Type    | Required | Description         |
 |-----------|---------|----------|---------------------|
-| `id`      | integer | yes      | The ID of a project |
+| `id`      | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 
 ```
 curl --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" "https://gitlab.example.com/api/v4/projects/1/pipelines"
@@ -45,7 +45,7 @@ GET /projects/:id/pipelines/:pipeline_id
 
 | Attribute  | Type    | Required | Description         |
 |------------|---------|----------|---------------------|
-| `id`       | integer | yes      | The ID of a project |
+| `id`       | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `pipeline_id` | integer | yes      | The ID of a pipeline   |
 
 ```
@@ -91,7 +91,7 @@ POST /projects/:id/pipeline
 
 | Attribute  | Type    | Required | Description         |
 |------------|---------|----------|---------------------|
-| `id`       | integer | yes      | The ID of a project |
+| `id`       | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `ref`       | string | yes      | Reference to commit |
 
 ```
@@ -137,7 +137,7 @@ POST /projects/:id/pipelines/:pipeline_id/retry
 
 | Attribute  | Type    | Required | Description         |
 |------------|---------|----------|---------------------|
-| `id`       | integer | yes      | The ID of a project |
+| `id`       | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `pipeline_id` | integer | yes   | The ID of a pipeline |
 
 ```
@@ -173,7 +173,7 @@ Response:
 }
 ```
 
-## Cancel a pipelines jobs 
+## Cancel a pipelines jobs
 
 > [Introduced][ce-5837] in GitLab 8.11
 
@@ -183,7 +183,7 @@ POST /projects/:id/pipelines/:pipeline_id/cancel
 
 | Attribute  | Type    | Required | Description         |
 |------------|---------|----------|---------------------|
-| `id`       | integer | yes      | The ID of a project |
+| `id`       | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `pipeline_id` | integer | yes   | The ID of a pipeline |
 
 ```
diff --git a/doc/api/project_snippets.md b/doc/api/project_snippets.md
index 4f6f561b83e..ff379473961 100644
--- a/doc/api/project_snippets.md
+++ b/doc/api/project_snippets.md
@@ -23,7 +23,7 @@ GET /projects/:id/snippets
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 
 ## Single snippet
 
@@ -35,7 +35,7 @@ GET /projects/:id/snippets/:snippet_id
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `snippet_id` (required) - The ID of a project's snippet
 
 ```json
@@ -67,7 +67,7 @@ POST /projects/:id/snippets
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `title` (required) - The title of a snippet
 - `file_name` (required) - The name of a snippet file
 - `code` (required) - The content of a snippet
@@ -83,7 +83,7 @@ PUT /projects/:id/snippets/:snippet_id
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `snippet_id` (required) - The ID of a project's snippet
 - `title` (optional) - The title of a snippet
 - `file_name` (optional) - The name of a snippet file
@@ -101,7 +101,7 @@ DELETE /projects/:id/snippets/:snippet_id
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `snippet_id` (required) - The ID of a project's snippet
 
 ## Snippet content
@@ -114,5 +114,5 @@ GET /projects/:id/snippets/:snippet_id/raw
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `snippet_id` (required) - The ID of a project's snippet
diff --git a/doc/api/projects.md b/doc/api/projects.md
index 686f3dba35d..63f88a464f5 100644
--- a/doc/api/projects.md
+++ b/doc/api/projects.md
@@ -18,6 +18,7 @@ Constants for project visibility levels are next:
   The project can be cloned without any authentication.
 
 
+
 ## List projects
 
 Get a list of visible projects for authenticated user. When being accessed without authentication, all public projects are returned.
@@ -157,8 +158,7 @@ Parameters:
 
 ### Get single project
 
-Get a specific project, identified by project ID or NAMESPACE/PROJECT_NAME, which is owned by the authenticated user.
-If using namespaced projects call make sure that the NAMESPACE/PROJECT_NAME is URL-encoded, eg. `/api/v3/projects/diaspora%2Fdiaspora` (where `/` is represented by `%2F`). This endpoint can be accessed without authentication if
+Get a specific project. This endpoint can be accessed without authentication if
 the project is publicly accessible.
 
 ```
@@ -169,7 +169,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer/string | yes | The ID or NAMESPACE/PROJECT_NAME of the project |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
 
 ```json
 {
@@ -295,7 +295,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer/string | yes | The ID or NAMESPACE/PROJECT_NAME of the project |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
 
 ```json
 [
@@ -497,7 +497,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer/string | yes | The ID or NAMESPACE/PROJECT_NAME of the project |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
 | `name` | string | yes | The name of the project |
 | `path` | string | no | Custom repository name for the project. By default generated based on name |
 | `default_branch` | string | no | `master` by default |
@@ -529,7 +529,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer/string | yes | The ID or NAMESPACE/PROJECT_NAME of the project |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
 | `namespace` | integer/string | yes | The ID or path of the namespace that the project will be forked to |
 
 ### Star a project
@@ -544,7 +544,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer/string | yes | The ID or NAMESPACE/PROJECT_NAME of the project |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
 
 ```bash
 curl --request POST --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" "https://gitlab.example.com/api/v4/projects/5/star"
@@ -609,7 +609,7 @@ POST /projects/:id/unstar
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer/string | yes | The ID of the project or NAMESPACE/PROJECT_NAME |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
 
 ```bash
 curl --request POST --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" "https://gitlab.example.com/api/v4/projects/5/unstar"
@@ -675,7 +675,7 @@ POST /projects/:id/archive
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer/string | yes | The ID of the project or NAMESPACE/PROJECT_NAME |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
 
 ```bash
 curl --request POST --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" "https://gitlab.example.com/api/v4/projects/5/archive"
@@ -757,7 +757,7 @@ POST /projects/:id/unarchive
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer/string | yes | The ID of the project or NAMESPACE/PROJECT_NAME |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
 
 ```bash
 curl --request POST --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" "https://gitlab.example.com/api/v4/projects/5/unarchive"
@@ -840,7 +840,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer/string | yes | The ID of the project or NAMESPACE/PROJECT_NAME |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
 
 ## Uploads
 
@@ -856,7 +856,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer/string | yes | The ID of the project or NAMESPACE/PROJECT_NAME |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
 | `file` | string | yes | The file to be uploaded |
 
 ```json
@@ -887,7 +887,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer/string | yes | The ID of the project or NAMESPACE/PROJECT_NAME |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
 | `group_id` | integer | yes | The ID of the group to share with |
 | `group_access` | integer | yes | The permissions level to grant the group |
 | `expires_at` | string | no | Share expiration date in ISO 8601 format: 2016-09-26 |
@@ -904,7 +904,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer/string | yes | The ID of the project or NAMESPACE/PROJECT_NAME |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
 | `group_id` | integer | yes | The ID of the group |
 
 ```bash
@@ -928,7 +928,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer/string | yes | The ID of the project or NAMESPACE/PROJECT_NAME |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
 
 ### Get project hook
 
@@ -942,7 +942,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer/string | yes | The ID of the project or NAMESPACE/PROJECT_NAME |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
 | `hook_id` | integer | yes | The ID of a project hook |
 
 ```json
@@ -975,7 +975,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer/string | yes | The ID of the project or NAMESPACE/PROJECT_NAME |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
 | `url` | string | yes | The hook URL |
 | `push_events` | boolean | no | Trigger hook on push events |
 | `issues_events` | boolean | no | Trigger hook on issues events |
@@ -1000,7 +1000,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer/string | yes | The ID of the project or NAMESPACE/PROJECT_NAME |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
 | `hook_id` | integer | yes | The ID of the project hook |
 | `url` | string | yes | The hook URL |
 | `push_events` | boolean | no | Trigger hook on push events |
@@ -1027,7 +1027,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer/string | yes | The ID of the project or NAMESPACE/PROJECT_NAME |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
 | `hook_id` | integer | yes | The ID of the project hook |
 
 Note the JSON response differs if the hook is available or not. If the project hook
@@ -1049,7 +1049,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer/string | yes | The ID of the project or NAMESPACE/PROJECT_NAME |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
 
 ```json
 [
@@ -1106,7 +1106,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer/string | yes | The ID of the project or NAMESPACE/PROJECT_NAME |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
 | `branch` | string | yes | The name of the branch |
 | `developers_can_push` | boolean | no | Flag if developers can push to the branch |
 | `developers_can_merge` | boolean | no | Flag if developers can merge to the branch |
@@ -1123,7 +1123,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer/string | yes | The ID of the project or NAMESPACE/PROJECT_NAME |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
 | `branch` | string | yes | The name of the branch |
 
 ### Unprotect single branch
@@ -1138,7 +1138,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer/string | yes | The ID of the project or NAMESPACE/PROJECT_NAME |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
 | `branch` | string | yes | The name of the branch |
 
 ## Admin fork relation
@@ -1155,7 +1155,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer/string | yes | The ID of the project or NAMESPACE/PROJECT_NAME |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
 | `forked_from_id` | ID | yes | The ID of the project that was forked from |
 
 ### Delete an existing forked from relationship
@@ -1168,7 +1168,7 @@ Parameter:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer/string | yes | The ID of the project or NAMESPACE/PROJECT_NAME |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
 
 ## Search for projects by name
 
diff --git a/doc/api/repositories.md b/doc/api/repositories.md
index b1bf9ca07cc..859cbd63831 100644
--- a/doc/api/repositories.md
+++ b/doc/api/repositories.md
@@ -13,7 +13,7 @@ GET /projects/:id/repository/tree
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `path` (optional) - The path inside repository. Used to get contend of subdirectories
 - `ref` (optional) - The name of a repository branch or tag or if not given the default branch
 - `recursive` (optional) - Boolean value used to get a recursive tree (false by default)
@@ -84,7 +84,7 @@ GET /projects/:id/repository/blobs/:sha
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `sha` (required) - The commit or branch name
 
 ## Raw blob content
@@ -98,7 +98,7 @@ GET /projects/:id/repository/blobs/:sha/raw
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `sha` (required) - The blob SHA
 
 ## Get file archive
@@ -112,7 +112,7 @@ GET /projects/:id/repository/archive
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `sha` (optional) - The commit SHA to download defaults to the tip of the default branch
 
 ## Compare branches, tags or commits
@@ -126,7 +126,7 @@ GET /projects/:id/repository/compare
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `from` (required) - the commit SHA or branch name
 - `to` (required) - the commit SHA or branch name
 
@@ -181,7 +181,7 @@ GET /projects/:id/repository/contributors
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 
 Response:
 
diff --git a/doc/api/runners.md b/doc/api/runners.md
index 46f882ce937..16d362a3530 100644
--- a/doc/api/runners.md
+++ b/doc/api/runners.md
@@ -222,7 +222,7 @@ GET /projects/:id/runners
 
 | Attribute | Type    | Required | Description         |
 |-----------|---------|----------|---------------------|
-| `id`      | integer | yes      | The ID of a project |
+| `id`      | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 
 ```
 curl --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" "https://gitlab.example.com/api/v4/projects/9/runners"
@@ -259,7 +259,7 @@ POST /projects/:id/runners
 
 | Attribute   | Type    | Required | Description         |
 |-------------|---------|----------|---------------------|
-| `id`        | integer | yes      | The ID of a project |
+| `id`        | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `runner_id` | integer | yes      | The ID of a runner  |
 
 ```
@@ -290,7 +290,7 @@ DELETE /projects/:id/runners/:runner_id
 
 | Attribute   | Type    | Required | Description         |
 |-------------|---------|----------|---------------------|
-| `id`        | integer | yes      | The ID of a project |
+| `id`        | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `runner_id` | integer | yes      | The ID of a runner  |
 
 ```
diff --git a/doc/api/tags.md b/doc/api/tags.md
index bf350f024f5..0f6c4e6794e 100644
--- a/doc/api/tags.md
+++ b/doc/api/tags.md
@@ -12,7 +12,7 @@ GET /projects/:id/repository/tags
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 
 ```json
 [
@@ -53,7 +53,7 @@ Parameters:
 
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
-| `id` | integer | yes | The ID of a project |
+| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `tag_name` | string | yes | The name of the tag |
 
 ```bash
@@ -93,7 +93,7 @@ POST /projects/:id/repository/tags
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `tag_name` (required) - The name of a tag
 - `ref` (required) - Create tag using commit SHA, another tag name, or branch name.
 - `message` (optional) - Creates annotated tag.
@@ -138,7 +138,7 @@ DELETE /projects/:id/repository/tags/:tag_name
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `tag_name` (required) - The name of a tag
 
 
@@ -153,7 +153,7 @@ POST /projects/:id/repository/tags/:tag_name/release
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `tag_name` (required) - The name of a tag
 - `description` (required) - Release notes with markdown support
 
@@ -174,7 +174,7 @@ PUT /projects/:id/repository/tags/:tag_name/release
 
 Parameters:
 
-- `id` (required) - The ID of a project
+- `id` (required) - The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user
 - `tag_name` (required) - The name of a tag
 - `description` (required) - Release notes with markdown support