Explain docstring ignore rules #1302

setup.cfg

@@ -10,9 +10,19 @@ tag_name = {new_version}
 
 [flake8]
 ignore = BLK100,E231,E731,W503,D100,D101,D102,D103,D400
-# D400 First line should end with a period
 
-# Excludes due to known issues or incompatibilities:
+# http://www.pydocstyle.org/en/2.1.1/error_codes.html
+# D100: Missing docstring in public module
+# D101: Missing docstring in public class
+# D102: Missing docstring in public method
+# D103: Missing docstring in public function
+# D400: First line should end with a period
+
+# Flake rules https://www.flake8rules.com/rules/E731.html:
+# E731: Do not assign a lambda expression, use a def
+
+# Excludes due to known issues or incompatibilities with black:
+# BLK100: Black would make changes. https://pypi.org/project/flake8-black/
 # W503: https://github.com/psf/black/search?q=W503&unscoped_q=W503
 # E231: https://github.com/psf/black/issues/1202