character-string

    OpenVMS usage:char_string
    type:         character string
    access:       read only
    mechanism:    by descriptor

    String whose initial character is used by LIB$LOCC in the
    search. The character-string argument contains the address of
    a descriptor pointing to this string. Only the first character of
    character-string is used, and its length is not checked.

 source-string

    OpenVMS usage:char_string
    type:         character string
    access:       read only
    mechanism:    by descriptor

    String to be searched by LIB$LOCC. The source-string argument is
    the address of a descriptor pointing to this character string.