1 files changed, 9 insertions, 0 deletions
diff --git a/lib/sqlalchemy/orm/base.py b/lib/sqlalchemy/orm/base.py
index 66b7b8c2e..47ae99efe 100644
--- a/lib/sqlalchemy/orm/base.py
+++ b/lib/sqlalchemy/orm/base.py
@@ -209,6 +209,15 @@ EXT_CONTINUE, EXT_STOP, EXT_SKIP, NO_KEY = tuple(EventConstants)
 
 
 class RelationshipDirection(Enum):
+    """enumeration which indicates the 'direction' of a
+    :class:`_orm.Relationship`.
+
+    :class:`.RelationshipDirection` is accessible from the
+    :attr:`_orm.Relationship.direction` attribute of
+    :class:`_orm.Relationship`.
+
+    """
+
     ONETOMANY = 1
     """Indicates the one-to-many direction for a :func:`_orm.relationship`.