Undocumented functions of NTDLL

typedef struct _SYSTEM_MODULE {


  ULONG                Reserved1;
  ULONG                Reserved2;
  PVOID                ImageBaseAddress;
  ULONG                ImageSize;
  ULONG                Flags;
  WORD                 Id;
  WORD                 Rank;
  WORD                 w018;
  WORD                 NameOffset;
  BYTE                 Name[MAXIMUM_FILENAME_LENGTH];


} SYSTEM_MODULE, *PSYSTEM_MODULE;

Reserved1
Reserved (always 0xBAADF00D).
Reserved2
Reserved (always 0).
Address
Module address in virtual address space.
ImageSize
Size of module in virtual address space.
Flags
- ???
Id
0-based counter of results.
Rank
The same as Id (in global enumeration with NtQuerySystemInformation), or unknown.
w018
In process module enumeration with LdrQueryProcessModuleInformation always 0xFFFF, in other - unknown.
NameOffset
Offset in Name table to first char of module name. 
Name
Path to module.