[<>/]   # char that is "<", ">" or "/"

##</code><code>##

[^<>/]   # char that isn't "<", ">" or "/"

##</code><code>##

use Test::More tests => 2;

$comment = '<Comment>foo bar</Comment>';
ok( $comment =~ m{<Comment>[^<>/]*</Comment>}, 'Detect no specials');

$comment = '<Comment>foo < bar</Comment>';
ok( $comment !~ m{<Comment>[^<>/]*</Comment>}, 'Detect <');

##</code><code>##

$ perl -MTest::Harness -e'runtests @ARGV' 808525.t
808525.t .. ok
All tests successful.
Files=1, Tests=2,  0 wallclock secs
Result: PASS