Q: :0 woah. What do you call a I,IV,V
A: 1, 4, 5 (by the way this is off the subject but if you are talking about a 4 bar chord sequence, in my opinion you really need to list all 4 bars, indicating which chord is doubled. such as 1, 1, 4, 5 or 1, 4, 5, 5. there is a huge difference depending on the timing, and if no timing is otherwise listed, just simply saying 1, 4, 5 (or I,IV,V) leaves me feeling still 100% left out of what is actually going on, with a 95% suspicion that it is actually referring to one of the two aforementioned 4-bar sequences, and being completely unable to determine which)