pData (PVOID) - input

Pointer to file-system driver or spooler data.

Address of the user-supplied file-system driver argument data area when flag is 0 or 1. The meaning of the data is specific to the file-system driver. pData contains contiguous ASCIIZ strings; the first word of the buffer contains the number of ASCIIZ strings. When flag is 2, pData points to the structure as follows:

hNmPipe (USHORT)

Handle of named pipe opened by spooler
cbSpoolObj (BYTE)
Length of name of spooler object (excluding NULL)
szSpoolObj (UCHAR)
Name of spooler object
When flag is 3, pData is set to zero.