{   This procedure is called to write tapemarks which delimit label groups on
{ a tape.
{
{   It allows writing of tapemarks after the end of volume has been
{ encountered.  This procedure bypasses data buffered by block management
{ which occurs when forced_write is not being used on calls to
{ BAP$TAPE_BM_WRITE_NEXT_BLOCK and BAP$TAPE_BM_WRITE_TAPE_MARK.
{
{   No buffering is done for this tapemark writing - the tapemark is written
{ to tape before this procedure returns.  This allows the error information
{ returned by this procedure to refer to the tapemark currently being written.
{
{   Tape I/O errors are indicated by both an abnormal status and a value in
{ the tape_failure_isolation.  (The status returned is
{ BAE$WRITE_ERROR_THIS_BLOCK.) IF media_recovery is TRUE, the tape will be
{ positioned just bfore the tapemark which was just (improperly) written.  If
{ media recovery is FALSE, the tape will be positioned after the bad tapemark.
{
{   If the I/O operation completed successfully with an End of Tape condition
{ present a BAE$VOL_END_OPERATION_COMPLETED condition will be returned.
{
{   BAP$TAPE_BM_WRITE_LABEL_MARK(FILE_IDENTIFIER, MEDIA_RECOVERY,
{ FAILURE_ISOLATION, STATUS)
{
{   FILE_IDENTIFIER (Input):  The file identifier for the file.
{
{  MEDIA_RECOVERY:  (Input) TRUE to have the system attempt recovery from
{        media errors encountered when writing this label to tape.  FALSE to
{        suppress any attempt by the system to recover from media errors.
{
{  FAILURE_ISOLATION:  (Output) Detailed information on any tape I/O error.
{
{  STATUS: (output) Request status.
{
