OK it's not a classical bug ... :)

... but there is no "missing documentation reporting system" so you'll have to rely on bug reporting.

(sorry I assumed perlbug is well known)

IMHO you could even suggest an extended POD text and attach a diff, if you want.

UPDATE: I'm still not sure if an unspecified feature isn't a bug. If other well known POD parser like Pod::POM don't implement it, because the authors don't know about it, it's a real problem!