note Enlil The difference is that with <code>[]</code> is part of a character class, which means that anything (in this case a line) within the <code>[]</code> will constitute a match at this position. So in your code, <code>[htm|asp]</code> anything that contains any of the following characters will match:<code> h t m | a s p</code>. <p> On the other hand with parenthesis you are asking the regex engine to match anything with <code>htm</code> OR <code>asp</code>, and hence output.php doesn't match.<p> You might want to have a look at [doc://perlretut] and [doc://perlre] for more info. <p> -enlil 481801 481801