Reserved words

The following list indicates words you must not use for ColdFusion variables, user-defined function names, or custom tag names. Although you can safely use some of these words in some situations, you can prevent errors by avoiding them entirely.

  • Built-in function names, such as Now or Hash can be used as variable names except for the following functions:
    • ParameterExists      
    • PreserveSingleQuotes
    • QuotedValueList      
    • ValueList


You cannot use Built-in Function names as User-Defined Function names. You can, however, use Built-in Function names as User-Defined Function names, when you define the function in a cfc.

  • Scope names, such as Form or Session.
  • Operators, such as NEQ or IS. For more information, see Operators and expressions.
  • The following language elements are keywords in a script syntax:
    • for
    • default
    • switch
    • case
    • continue
    • import
    • finally
    • local (inside function declaration)
    • interface
    • pageencoding
    • return
    • try
    • catch
    • in
    • else  
    • if  
    • while    
    • do    
    • break
  • The following elements are reserved in both script and tags:
    • function
    • true
    • false
    • final
    • abstract
    • null – can be used as variable names but not as User-Defined Function name.
  • You cannot use cfimport as a variable in a script synatx.
  • You cannot use tag names as User-Defined Functions in both tags and script syntaxes.