Documentation Link

https://matplotlib.org/devdocs/devel/document.html#default-values

Problem

I feel strongly enough about this to create an issue: see the discussion between me and Elliott here: #31262 (comment)

In particular, this paragraph from "Write documentation" is well outside of the norm, in my experience:

If None is only used as a sentinel value for "parameter not specified", do not document it as the default. Depending on the context, give the actual default, or mark the parameter as optional if not specifying has no particular effect.