aclstr

    OpenVMS usage:char_string
    type:         character-coded text string
    access:       read only
    mechanism:    by descriptor-fixed-length string descriptor
    Formatted ACE that is parsed when $PARSE_ACL completes execution.
    The aclstr argument is the address of a string descriptor
    pointing to the text string to be parsed.

 aclent

    OpenVMS usage:char_string
    type:         character-coded text string
    access:       write only
    mechanism:    by descriptor-fixed-length string descriptor
    Description of the ACE that is parsed when $PARSE_ACL completes
    execution. The aclent argument is the address of a descriptor
    pointing to the buffer in which the ACE is written. The first
    byte of the buffer contains the length of the ACE; the second
    byte contains a value that identifies the type of ACE, which in
    turn defines the format of the ACE.

    For information about the ACE types and their associated formats,
    see $FORMAT_ACL system service documentation.

 errpos

    OpenVMS usage:word_unsigned
    type:         word (unsigned)
    access:       write only
    mechanism:    by reference
    Number of characters from aclstr processed by $PARSE_ACL. The
    errpos argument is the address of a word that receives the number
    of characters actually processed by the service. If the service
    fails, this count points to the failing point in the string.

 accnam

    OpenVMS usage:access_bit_names
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference
    Names of the bits in the access mask when $PARSE_ACL is
    executing. The accnam argument is the address of an array of
    32 quadword descriptors that define the names of the bits in the
    access mask. Each element points to the name of a bit. The first
    element names bit 0, the second element names bit 1, and so on.

    You can call LIB$GET_ACCNAM to retrieve the access name table
    for the class of object whose ACL is to be formatted. If you omit
    accnam, the following names are used:

    Bit    Name

    Bit 0  READ
    Bit 1  WRITE
    Bit 2  EXECUTE
    Bit 3  DELETE
    Bit 4  CONTROL
    Bit 5  BIT_5
    Bit 6  BIT_6
    .
    .
    .
    Bit    BIT_31
    31

 nullarg

    OpenVMS usage:null_arg
    type:         longword (unsigned)
    access:       read only
    mechanism:    by value
    Placeholding argument Reserved to VSI.