Texas Hold'em Casinos/WSOP/ WTP/ Vegas Rules-definitive standard?

[texasholdem2]

I tried the search feature on this but really couldn't find anything directly relating to my question so.....

Is Roberts Rules of Poker the definitive rule book used for Texas Hold'em tournaments and cash games? If not, is there another standard? Also is it not unusual for rules to vary from casino to casino and between major poker tournaments such as the WSOP and WTP?

I guess what I'm trying to get at is there a definitive rule book for Texas Hold'em that all dealers and floor men should know and abide by religiously?

Many Thanks,
Mike