A Genero BDL identifier is a sequence of characters used to identify a program entity.

An identifier must conform to the following rules:

  • It must include at least one character, without any limitation in size.
  • Only ASCII letters, digits, and underscore ( _ ) symbols are valid.
  • Blanks, hyphens, and other non-alphanumeric characters are not allowed.
  • The initial character must be a letter or an underscore.
  • Common identifiers are not case sensitive, so my_Var and MY_vaR both denote the same identifier. However, in some cases, identifiers are case sensitive (like action names in the AUI tree). It is recommended to always write identifiers in lower case to avoid mistakes.

Within non-English locales, BDL identifiers can include non-ASCII characters in identifiers, if those characters are defined in the code set of the current locale. In multibyte East Asian locales that support languages whose written form is not alphabet-based (such as Chinese, Japanese, or Korean), an identifier does not need to begin with a letter. It is however recommended to program in ASCII.