I'm while using following ModRewrite to create my web addresses look cleaner:

RewriteEngine On
RewriteRule ^([a-zA-Z0-9_-]+)/?$ index.php?key=$1

It enables utilization of letters and amounts all right, however it creates a 400 error after i use %, that we desire to use unicode figures for # / ', etc. Any cause of this? Thanks.

you need to use B flag inside your rewrite rule. have a look at apache manual .

RewriteEngine On
RewriteRule ^([a-zA-Z0-9_-#$%^&]+)/?$ index.php?key=$1 [B]

Edit: mod_rewrite uses unescaped figures, so if you wish to use unicode figures, rely on them in rewrite rule and save .htaccess file in unicode!