Perl as a language is a strange beast. It does whatever it does, and that may change highly between versions. In this way it doesn't lend itself at all to be standarized. Additionally, the most up-to-date specification of Perl (If you could call it that) is the documentation behind Perl 6. We are certainly not in a position currently to standardize support for Perl 6.

This leads to the conclusion that it isn't really the language, Perl, that is currently a de facto Linux standard. It's the application, perl, which is commonly used. In the Linux world, perl is everywhere, and any programmer can make a reasonable expectation to find perl 5.8 on a new system as released by the distribution designers. In this way, perl belongs to the "Commands and Utilities" section of the LSB, as listed here: http://refspecs.freestandards.org/LSB_3.1.0/LSB-Core-generic/LSB-Core-generic/toccommand.html

After that outlook on perl, in relation to the LSB, has been established, the details are easy. Beyond having support for all the basic aspects of the Perl language, core modules need to be installed, and a language specification isn't needed. Basically what I mean to say in my humble, practical opinion, is that not much more is needed to pass realistic standards than having a modern /usr/bin/perl (5.8, heck, 5.6!) and core modules somewhere.

Just my two cents.