Any versions of ICAO Doc 8168, especially Vol. 2, that are online, will most likely be well out of date. Use at your own risk. ICAO sells it and deliberately doesn't make it available for online download so, if you want the absolute latest - as you should - you're far safer to BUY a subscription from ICAO.
This manual is really intended for those who will use it to develop instrument procedures. It's not light reading!