Reserved words and variables CFML includes reserved words and scope variables. Reserved words Words you must not use for ColdFusion variables, user-defined function names, or custom tag names. Scope-specific built-in variables Scope variables used in ColdFusion. Custom tag variables Custom tag variables in ColdFusion. ColdFusion tag-specific variables ColdFusion tags that return data, which you can reference in variables. CGI environment (CGI Scope) variables CGI environment (CGI Scope) variables. Some content linked from this page may appear in English only.