Source : Free On-Line Dictionary of Computing

Extended System Configuration Data
     
         (ESCD) An area of memory, not exceeding 32
        kilobytes in size, used by {MS-DOS}(?) as {NVRAM} for {PNP
        BIOS} and {PNP OS}.  It must be writeable at {run time}.
     
        Intel's {ICU} also uses ESCD to store information for PNP
        {ISA} cards and {legacy} ISA cards.
     
        (1999-11-22)