This structure is used in the following IOCTL fns:
    440cH 4cH (start code page prepare)
    DvRq 13H  (generic IOCTL for character devices)

  Offset Size Contents
  ▀▀▀▀▀▀ ▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀
    +0     2  rDevFlags    device-specific bit flags
    +2     2  wLength      length of the rest of this structure;
                             ( (wCpIdCnt * 2) + 2)
    +4     2  wCpIdCnt     the number of items in awCpIds array
    +6   n*2  awCpIdList   variable-length series of code page numbers
        (n*2)+6            length of an IoctlCpPrepRec structure

 There may be up to 12 items in the awCpIdList field in the structure,
 depending on parameter values specified when the driver was installed.

 If any of the elements in awCpIdList is ffffH, it tells the device driver
 to NOT modify the code page at that position in its own list.

See Also: fn 440cH (Generic IOCTL for character devices)
          National Language Support
          Device Drivers
          DOS Functions