Yes, you are correct; I hadn't thought of doing it that way. You could make a separate User Defined Language (UDL) for each version of Perl, and define a separate autocompletion file for each of those Perl-version UDLs. Since the UDL features aren't as powerful as the built-in lexers, you would then be sacrificing some of the syntax-highlighting capabilities and subtleties in order to gain the specific results in the auto-completion suggestions. Knowing those tradeoffs, and understanding the cost (time and effort) involved in creating all those UDL and autocompletion files, any particular user could make the decision of which way to go for themselves.