The Free On-line Dictionary of Computing (30 December 2018):

DOS Protected Mode Interface
DPMI

   (DPMI) The method which Microsoft prescribes for a DOS
   program to access extended memory under a multitasking
   environment, e.g. Microsoft Windows.  This service is
   provided by the HIMEM.SYS driver on IBM PCs.

   The DPMI specification was finalized in 1990.  The
   specification itself is available from Intel Literature
   Sales.

   VCPI (Virtual Control Program Interface), which was an
   alternative, and incompatible method for doing the same thing.

   ["Windows 3.1 Secrets", Brian Livingston, 1992, ISBN
   1-878058-43-6, pages 280-281 and 302].

   (1995-01-12)