http://i3xi5qxvbrngh3g6o7czwjfxwjzigook7zxzjmgwg5b7xnjcn5hzciad.onion/version-spec.html
The New Way Starting at 0.1.0.1-rc, versions are of the format: MAJOR.MINOR.MICRO[.PATCHLEVEL][-STATUS_TAG][ (EXTRA_INFO)]* The stuff in parentheses is optional. As before, MAJOR, MINOR, MICRO,
and PATCHLEVEL are numbers, with an absent number equivalent to 0.
All versions should be distinguishable purely by those four
numbers. The STATUS_TAG is purely informational, and lets you know how
stable we think the release is: “alpha” is pretty unstable; “rc” is...