That's pretty much what I meant yes. There are major changes in Perl 6's rules anyway (like square brackets actually, which go from character class to grouping), so expecting metacharacters to have the same meaning might lead to some trouble. But as stated in ambrus's answer, that's not only what Perl user would expect, it's what a lot of people using other languages would expect. Still, Perl 6's rules would be quite the surprise, because one would expect Perl of all languages to be compatible with PCRE. But actually, one of the main focuses of apocalypse 5 is to mend whatever went wrong with Perl regexes, and PCRE.