Hi,
I read man mt to operate tape drive. And I felt difference between description and behavior.
I suggest improvement of man page description.


1. bsf

>       fsf    Forward space count files.  The tape is positioned on the first
>              block of the next file.
>       bsf    Backward space count files.  The tape is positioned on the first
>              block of the next file.

In this description, both fsf and bsf seem to move to the first block of the next file.

But bsf backs EOF and stop at between last block of previous file and EOF.

I suggest that following description is better:

>       bsf    Backward space count files.  The tape is positioned on the last
>              block of the previous file.

2. bsfm

>       fsfm   Forward space count file marks.  The tape is positioned  on  the
>              beginning-of-the-tape side of the file mark.
>       bsfm   Backward  space count file marks.  The tape is positioned on the
>              beginning-of-the-tape side of the file mark.

In this description, both fsfm and bsfm seem to move to the beginning-of-the-tape side of the file mark.

But bsfm backs EOF and reposition to the end-of-the-tape side of the file mark.

Also man st says:

> MTBSFM       Backward space over mt_count filemarks.  Reposition the tape to the
>              EOT side of the last filemark.

I suggest that following description is better:

>       bsfm   Backward  space count file marks.  The tape is positioned on the
>              end-of-the-tape-side of the file mark.

Tape structure and stop positions as I understand:
~--+-----+-----+-----+-----+-----+-----+-----+-~
  file 1 data blocks | EOF | file 2 data blocks
~--+-----+-----+-----+-----+-----+-----+-----+-~

fsf
 ------------------------->^ stops here
  the first block of next file (file 2)

bsf
          stops here ^<-------------------------
  the last block of previous file (file 1)

fsfm
     ----------------------> comes here
                     ^<----  and turns back, stops here
  the beginning-of-the-tape side of the file mark

bsfm
         comes here  <--------------------------
                     ----->^ and turns back, stops here
  the end-of-the-tape-side of the file mark


Regards,