

  TYPE
    { Usage sanctions may be used to prevent certain kinds of logical or
    {physical}
    { operations on a logical unit.}
    {}
    { Inhibit_logical_mount prevents label-searching of the medium mounted on}
    { the unit. This allows the operator to 'idle' a unit. By itself, this}
    { sanction does not prevent physical i/o operations, other than}
    { label-searching. Thus, when all jobs previously using the medium have}
    { stopped doing so, the medium is in a state where it may be logically}
    { dismounted.}
    {}
    { Inhibit_read_request and/or inhibit_write_request may be used to prevent}
    { physical i/o requests submitted on behalf of a program. These sanctions}
    { do not prevent low-level NOSVE physical i/o requests performed for such}
    { reasons as label-searching or volume-initialization. Both the read and}
    { write sanctions would be set if a unit which had been logically mounted}
    { incurred a ready/not-ready state change. These sanctions would prevent}
    { program access to the unit until NOSVE is certain that the correct}
    { volume is mounted. A use of this feature which is appropriate to a tape}
    { unit is to make it a read-only unit. A site could also designate}
    { certain units to be a read-only source of permanent files.}
    {}
    cmt$usage_sanctions = set of cmt$device_usage_sanctions,

    cmt$device_usage_sanctions = (cmc$inhibit_logical_mount,
      cmc$inhibit_read_request, cmc$inhibit_write_request);
