Int 2F Fn B711  - Dos 4.0+ Append - Set Return Found Name State            [f]

   AX = B711h

Note:  if the next INT 21h call (and ONLY the next) is function 3Dh, 43h, or
     6Ch (also 4B03h and 4Eh if /X active), the fully qualified filename
     is written over top of the filename passed to the INT 21h call.  The
     application must provide a sufficiently large buffer.  This state is
     reset after the next INT 21h call processed by APPEND.
   APPEND uses the byte at offset 3Dh in the PSP
     (see #1066 at INT 21/AH=26h) to store the flag telling it to
     overwrite the filename
BUG:   DOS 4.0 APPEND reportedly overwrites DS:DX instead of DS:SI for
     INT 21/AH=6Ch

See Also: INT 21/AH=26h,INT 21/AH=4Eh