typedef enum _POOL_TYPE
{
         NonPagedPool = 0,
         PagedPool = 1,
         NonPagedPoolMustSucceed = 2,
         DontUseThisType = 3,
         NonPagedPoolCacheAligned = 4,
         PagedPoolCacheAligned = 5,
         NonPagedPoolCacheAlignedMustS = 6,
         MaxPoolType = 7,
         NonPagedPoolSession = 32,
         PagedPoolSession = 33,
         NonPagedPoolMustSucceedSession = 34,
         DontUseThisTypeSession = 35,
         NonPagedPoolCacheAlignedSession = 36,
         PagedPoolCacheAlignedSession = 37,
         NonPagedPoolCacheAlignedMustSSession = 38
} POOL_TYPE;

Windows Vista Kernel Structures