number-of-descriptors

    OpenVMS usage:longword_unsigned
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference

    Number of adjacent descriptors freed by LIB$SFREEN_DD. The
    number-of-descriptors argument contains the address of an
    unsigned longword that is this number. The deallocated area is
    returned to free storage.

 first-descriptor-array

    OpenVMS usage:descriptor_array
    type:         quadword (unsigned)
    access:       modify
    mechanism:    by reference, array reference

    First descriptor of an array of descriptors. The first-
    descriptor-array argument contains the address of this first
    descriptor. The descriptors are assumed to be dynamic, and their
    class fields are not checked.

    The descriptor array must contain all 32-bit descriptors or all
    64-bit descriptors. They cannot be mixed.