Wildcards in versions
From the PMS section 8.2.6.1:
=
Exactly equal to the specified version. Special exception: if the version specified has an asterisk immediately following it, then only the given number of version components is used for comparison, i. e. the asterisk acts as a wildcard for any further components. When an asterisk is used, the specification must remain valid if the asterisk were removed. (An asterisk used with any other operator is illegal.)
This is useful for relying on major or minor versions, and I must have missed it when I first wrote the version comparison code.
E.g. you can write =cat/foo-3*
to mean <cat/foo-4 >=cat/foo-3