Previously what I've read is that it's 3 continuous years of residency prior to international debut, with holidays being excluded, but not working/living overseas, with some sort of exemption for 5+ years when being U18.
Edit: No exemptions:
Subject to Regulation 8.2, a Player may only play for the senior fifteen-aside National Representative Team, the next senior fifteen-a-side National Representative Team and the senior National Representative Sevens Team of the Union of the country in which:
(a) he was born; or
(b) one parent or grandparent was born; or
(c) he has completed thirty six consecutive months of Residence immediately preceding the time of playing.
I think you're allowed to be out of the country for 3 months. From memory I thought Speight was only disqualified because, after the ITM cup he went on holidays somewhere without returning to Australia. That's at least in my memory for some reason, could be very wrong.
my concern with the new signing from NRL is that Rebels are going down the marquee player strategy (again - paying big bucks for one player who they put their trust in to win the game) which possibly alienates other home grown players - Sefa, Sione, and others who have been in the team for some time but at much less pay rate. Do you think there might be some resentment? which might result in disharmony on field rather than support?