Yes, I have read all those articles on the internet. But nowhere was described this counterintuitive behaviour. Of course, they point out that perl -we'my @l = qw/ac qw/; for (@l) { print if /a/../c/ }' would print
ac and the same only with three dots prints acqw. This is completely understandable but not the case with @l = qw/ca qw/. Maybe it's really better to avoid such constructs as other monk has said.