identifier

    Specifies the identifier to be converted. Specify the identifier
    as an integer expression if you are converting an integer to a
    name. Specify the identifier as a character string expression if
    you are converting a name to an integer.

    Any identifier holding the Name Hidden attribute will cause
    the F$IDENTIFIER to return an error when you do not hold the
    identifier in question or do not have access to the rights
    database. For further information on the attribute, see the VSI
    OpenVMS Guide to System Security.

 conversion-type

    Indicates the type of conversion to be performed. If the
    identifier argument is alphanumeric, specify the conversion-type
    argument as a character string containing "NAME_TO_NUMBER". If
    the identifier argument is numeric, specify the conversion-type
    argument as a character string containing "NUMBER_TO_NAME".