KEY_NAME_INFORMATION - NtDoc

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

/**
 * The KEY_NAME_INFORMATION structure holds the name and name length of the key.
 * \sa https://learn.microsoft.com/en-us/windows-hardware/drivers/ddi/ntddk/ns-ntddk-_key_name_information
 */
typedef struct _KEY_NAME_INFORMATION
{
    ULONG NameLength;                               // The size, in bytes, of the key name string in the Name array.
    _Field_size_bytes_(NameLength) WCHAR Name[1];   // The name of the registry key. This string is not null-terminated.
} KEY_NAME_INFORMATION, *PKEY_NAME_INFORMATION;

#endif

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This structure is documented in Windows Driver Kit.