Ah, ok! Need to look those up also then. I think he is in the Math Olympiad training in school, though I have not heard of him taking part in any competitions.
Time for me to stop arguing about Phase 2a and get about sussing these things out!
Your son is in P4? Many of the Olympiads take place in P5. Plenty of time to get your son ready. NMOS is good for NUSH, Mathlympics for ACSI, SMOPS for all schools. RI's Math Olympiad is the toughest to score in.