Int 22  - DOS 1+ - Program Termination Address                             [!]

Desc:  this vector specifies the address of the routine which is to be given
     control after a program is terminated; it should never be called
     directly, since it does not point at an interrupt handler

Notes: this vector is restored from the DWORD at offset 0Ah in the PSP during
     termination, and then a FAR JMP is performed to the address in INT 22
   normally points at the instruction immediately following INT 21/AH=4Bh
     call which loaded the current program

See Also: INT 20,INT 21/AH=00h,INT 21/AH=31h,INT 21/AH=4Ch