RtlNormalizeSecurityDescriptor - NtDoc

Native API online documentation, based on the System Informer (formerly Process Hacker) phnt headers
#ifndef _NTRTL_H
#if (PHNT_VERSION >= PHNT_19H2)

__drv_maxIRQL(APC_LEVEL)
NTSYSAPI
BOOLEAN
NTAPI
RtlNormalizeSecurityDescriptor(
    _Inout_ PSECURITY_DESCRIPTOR *SecurityDescriptor,
    _In_ ULONG SecurityDescriptorLength,
    _Out_opt_ PSECURITY_DESCRIPTOR *NewSecurityDescriptor,
    _Out_opt_ PULONG NewSecurityDescriptorLength,
    _In_ BOOLEAN CheckOnly
    );

#endif
#endif

View code on GitHub

This function is documented in Windows Driver Kit.