Documentation Link

https://matplotlib.org/devdocs/api/_api_api.html?highlight=deprecation#matplotlib._api.deprecation.warn_deprecated

Problem

I'm deeply confused about whether since is the last release that has the arg or the first release without it. It's documented as The release at which this API became deprecated. which I assume is following some convention, but is not clear to me since I do not know the convention.

Suggested improvement

Add a sentence to the since docstring (and possibly to https://matplotlib.org/devdocs/devel/contributing.html#api-changes) saying something like: the last release containing this code. I think https://docs.moodle.org/dev/Deprecation do a good job at illustrating the convention.

Edit: as @QuLogic suggested, don't modify the docstring but explain the deprecation to removal process more explicitly in the API changes part of the dev guide.

Matplotlib Version

dev

Matplotlib documentation version

dev