Having editor hints in the source can have value as it can reduce the cage cleaning load by getting the editor to indent people's code consistently (admittedly this only helps people who use emacs and vim in this case) so in that sense it is worthwhile having them around. The coda is added to all C-language files; the problem is only with Perl-language files with __END__ and __DATA__ blocks. Why don't we just let them be an exception which doesn't require such editor hints?
Just my $0.02 Paul
