How do I downvote / borg myself?

However (conveniently bypassing the requirement for names beginning with __):

#!/usr/bin/perl
use warnings;
use strict;
# 744661 

my @var = ( 'foo.Bar',
      'for.bar',
    );

for my $var(@var) {
    print "Before regex, \$var: $var \n";
    if ( $var =~ /^([-!#.0-9@-Z_a-z]+)$/ ) {
        print "\$var: $var\n";
    } else {
         print "no match!\n";
    }
}
[download]

produces:

Before regex, $var: foo.Bar
no match!
Before regex, $var: for.bar
$var: for.bar
[download]

whereas using /i in the regex at line 12:

Before regex, $var: foo.Bar
$var: foo.Bar
Before regex, $var: for.bar
$var: for.bar
[download]

leaving me to wonder about the "shorthand."

Oops. It took me a while to figure out that you were using square brackets. By the time I figured that out, it looks like I had changed from [@-Z] (interpolation of var @- plus "Z") to [\@-Z] (short for [\@A-Z]).

In ASCII-based encodings, "@" is "\x40", the character before "A".