RTL_MEMORY_TYPE - NtDoc

Native API online documentation, based on the System Informer (formerly Process Hacker) phnt headers
#ifndef _NTRTL_H

// Segment heap parameters.

typedef enum _RTL_MEMORY_TYPE
{
    MemoryTypePaged,
    MemoryTypeNonPaged,
    MemoryType64KPage,
    MemoryTypeLargePage,
    MemoryTypeHugePage,
    MemoryTypeCustom,
    MemoryTypeMax
} RTL_MEMORY_TYPE, *PRTL_MEMORY_TYPE;

#endif

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This enumeration is documented in Windows Driver Kit.