RtlIsCapabilitySid

UINT8 __stdcall RtlIsCapabilitySid(VOID *Sid){
  return *((_BYTE *)Sid + 1) >= 2u
      && *(_BYTE *)Sid == 1
      && RtlCompareMemory((char *)Sid + 2, &RtlpAppPackageAuthority, 6) == (_SIZE_T *)6
      && *((_DWORD *)Sid + 2) == 3;
}

Referenced by:

NtCreateLowBoxToken
RtlCheckTokenCapability
SepFilterToken