Don't redo it from scratch... just select one of the validations already on the page and click the edit icon. Then add the additional characters you would like allowed for that field in the space provided.
I've attached a screen grab to help illustrate.
![](/forums/attachments/193516/cache/var/www/vhosts/webassist.com/user_uploads/forums/attachments/193516/proportion/edit_server_validations_w104_h100/edit_server_validations_11170737.png)