[arch-general] Question on version numbers

Hi, just because I'm inquisitive. What's the purpose of version numbers with a colon? I've seen this in several packages, e.g. this one [1]. Upstream version number is 5.0.2 and arch version number is 1:5.0.2. Regards, Stefan [1]: https://www.archlinux.org/packages/extra/any/python-setuptools/