Seems like the Cisco Multicast Command reference guide has gone missing.
here's the page for the 15.3 version.
http://www.cisco.com/c/en/us/support/ios-nx-os-software/ios-15-3m-t/products-installation-and-configuration-guides-list.html
I've tried all the different versions from 12.4 up and its missing.
You can google it but the link comes up as a missing doc.
Anyone is cisco know if somethings changed or if anyone is aware of this?