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. The main purpose of this template is to detect whether a template parameter has already been linked manually.
Examples
{{isValidPageName|Main Page}}returns ""{{isValidPageName|[[Main Page]]}}returns ""{{isValidPageName|This page could not POSSIBLY exist, could it?}}returns ""{{isValidPageName|-}}returns "" (even though "-" can exist){{isValidPageName}}returns ""