Update contribution guidelines

1 files changed, 4 insertions, 0 deletions

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 7b19d7a..830fbcb 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -77,6 +77,8 @@ These coding styles are encouraged whether submitting code for core pyparsing or
                           + some_other_long_thing
                           + even_another_long_thing)
 
+- Maximum line length is 120 characters.
+
 - Changes to core pyparsing must be compatible back to Py3.5 without conditionalizing. Later Py3 features may be
   used in examples by way of illustration.
 
@@ -92,6 +94,8 @@ These coding styles are encouraged whether submitting code for core pyparsing or
       ppc = pp.pyparsing_common
       ppu = pp.pyparsing_unicode
 
+  Submitted examples *must* by Python 3 compatible.
+
 - Where possible use operators to create composite parse expressions:
 
       expr = expr_a + expr_b | expr_c