Area properties provide additional control over file or area
    space allocation on disk devices to optimize performance.

    You usually include areas using indexed files. A file can contain
    up to 255 areas. Define areas in numerical order, beginning with
    0.

    For a description and valid values for a particular keyword, see
    the OpenVMS documentation on RMS.

    For a mapping of CDO keywords to symbolics, see RMS_Keyword_
    Mapping_Tables.