Reserved words in ColdFusion

As with any programming tool, you cannot use just any word or name for ColdFusion variables, UDFs and custom tags. Avoid using any name that can be confused with a ColdFusion element. In some cases, if you use a word that ColdFusion uses — for example, a built-in structure name — you can overwrite the ColdFusion data.
The following list indicates words you must not use for ColdFusion variables, user-defined function names, or custom tag names. While some of these words can be used safely in some situations, you can prevent errors by avoiding them entirely. For a complete list of reserved words, see the CFML Reference.

• Built-in function names, such as Now or Hash
• Scope names, such as Form or Session
• Any name starting with cf. However, when you call a CFML custom tag directly, you prefix the custom tag page name with cf_.
• Operators, such as NE or IS
• Names such as Function, Abstract, or Null.

           Note: If this.enableNullSupport = true, you cannot use Null as a keyword.

• The names of any built-in data structures, such as Error or File
• The names of any built-in variables, such as RecordCount or CGI variable names
• CFScript language element names such as for, default, or continue
  Also, do not create form field names ending in any of the following, except to specify a form field validation rule using a hidden form field name. (For more information on form field validation, see Introduction to Retrieving and Formatting Data.)

• _integer
• _float
• _range
• _date
• _time
• _eurodate
  Because ColdFusion is not case-sensitive, all of the following are reserved words: IS, Is, iS, and is.

• The following language elements are keywords in a script syntax:
  • for
  • default
  • switch
  • case
  • continue
  • import
  • finally
  • final
  • 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.