NtDeletePrivateNamespace - NtDoc

#ifndef _NTOBAPI_H
// Private namespaces
#if (PHNT_MODE != PHNT_MODE_KERNEL)
#if (PHNT_VERSION >= PHNT_VISTA)

NTSYSCALLAPI
NTSTATUS
NTAPI
NtDeletePrivateNamespace(
    _In_ HANDLE NamespaceHandle
    );

#endif
#endif
#endif
View code on GitHub

#ifndef _NTZWAPI_H

NTSYSCALLAPI
NTSTATUS
NTAPI
ZwDeletePrivateNamespace(
    _In_ HANDLE NamespaceHandle
    );

#endif
View code on GitHub