.htaccess RewriteRule

// An example of negation. Everything except the stuff in ?!(here|and|here) is routed to index.php // So for this example: all local stylesheets, javascript, photos, fonts, and captcha will still work. // You MUST be careful and diligent if you wish to use this method--new features could break--but it works well. RewriteEngine on RewriteRule ^(.(?!(.css|.js|.png|.jpg|.gif|.webm|.svg|.cur|.eot|.woff|.ttf|captcha.php)$))*$ index.php

Character Limit

// An example of limiting characters. ^.{7,64}$

Usernames

// An example of validating usernames. For conveinence only; not to be used for security purposes! // This is lowercase/uppercase letters, and numbers. Four to sixty-four characters long. ^[a-zA-Z0-9]{4,64}$