This structure is used in the following IOCTL fns:
DvRq 13H (generic IOCTL for character devices)
+0 2 rDevFlags device-specific bit flags
+2 2 wLength length of the rest of this structure;
+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)