A few months ago, PEP 753 was accepted. It is now known as the "Well-known Project URLs in Metadata" standard. We should implement it as pip does consume project URL metadata.

I haven't looked at pip's existing Project-URL or Home-page handling, so it's possible that there is very little or nothing to do on pip's end, but I wanted to file this issue to make sure we take a look at some point. The logic that mirrors PyPI's old homepage Project-URL aliasing probably needs a some tweaking to have it conform to the specification.

cc @woodruffw