RtlFreeSid - NtDoc

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

NTSYSAPI
PVOID
NTAPI
RtlFreeSid(
    _In_ _Post_invalid_ PSID Sid
    );

#endif

View code on GitHub

This function is documented in Windows Driver Kit.