As Perl evolves, new desirable features get added. The best ones seem to
break backward compatibility, unfortunately. As a favor to downstream
developers, its good to state explicitly which Perl version will not be able
to parse your code.
For example, the our keyword was first appeared in a stable Perl in version
5.6.0. Therefore, if your code employs our, then you should have a line
like this near the very top of your file:
The former is preferred as the latter can trigger v-string compatibility
warnings. (If someone could please explain that to me, Id really appreciate
Additionally, its good form to state that minimum version in your
Makefile.PL or Build.PL file.