key-code
    OpenVMS usage:word_unsigned
    type:         word (unsigned)
    access:       read only
    mechanism:    by reference
    Specifies the key code to translate into a key name. The key-code
    argument is the address of an unsigned word that contains the key
    code.
    The key code is returned by SMG$READ_COMPOSED_LINE, SMG$READ_
    KEYSTROKE, SMG$READ_STRING, and SMG$READ_VERIFY in the word-
    terminator-code argument.
 key-name
    OpenVMS usage:char_string
    type:         character string
    access:       write only
    mechanism:    by descriptor
    String containing the name of the key into which key-code is
    to be translated. The key-name argument is the address of a
    descriptor pointing to the character string containing the key
    name. The key-name argument is simply the name of the key (for
    example, COMMA, PERIOD, KP4, and so forth).