Just to check out my suspicions, I searched CPAN for five modules that my copy of perlmodlib said are standard with 5.8.7.
in reply to Re^2: CPAN: standard modules and other modules
in thread CPAN: standard modules and other modules
Only three of these are linked back to the distribution Perl 5.8.7, the other two are found as separate distributions. Not even the listing of modules with Perl 5.8.7 shows the other two modules. Only by looking in the perlmodlib of that release can you find them listed.
I have to agree that it would be very nice to see the addition of a "Standard since Perl 5.8.3" information line. It would seem all the information needed is in Module::CoreList as mentioned above. I can see that it might be required for some modules to mention more than one release, something like "Standard since Perl 5.7.3, 5.8.0", when the release dates are staggered.