This template is used on 2,200+ pages and changes may be widely noticed. Test changes in the template's /sandbox or /testcases subpages, or in your own user subpage. Consider discussing changes on the talk page before implementing them.
This template returns "valid" if the given page title is valid, or the empty string otherwise. The page does not need to exist in order for the template to return "valid". As a convenience, the template treats "-" as an invalid page title.