first-source-string

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

    First string. The first-source-string argument is the address of
    a descriptor pointing to the first string.

 second-source-string

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

    Second string. The second-source-string argument is the address
    of a descriptor pointing to the second string.