> I’m not sure I understand what you mean by “tag”.

>> funcname(args)  [new in 3.2] [deprecated in 3.5]
>>   Func description here.

I mean some kind of tag/label next to the name of the function in the documentation (red/orange for deprecations, green for new-in)  -- it's not a Sphinx-specific term.
I saw it in some other documentation but I can't find it anymore, however if you look at the [task] and [assigned] tags/labels at the top of https://twistedmatrix.com/trac/ticket/5000 you can get a pretty close idea of what I'm thinking about.

> Are you saying that the source documentation would remain as-is,
> but something during the Sphinx _transformation_ would generate
> the new/deprecated tags?  

That's the idea.  Ideally the func/meth/class directives [0] would add the tags/labels if they contain version-added/version-changed/deprecated/deprecated-remove directives.

[0]: directives look like ".. function:: foo(args)", whereas roles look like :func:`foo`.  Functions are defined using directives.  In the previous message I mistakenly said "roles".  See also https://docs.python.org/devguide/documenting.html#directives