I'm not sure there is one. If you look at the BS rule book (haven't looked at the FEI one) you can see table 136 limits JA's to 1.40; JCs to 1.30; 138s to 1.15 and 128s to 1.05 in the first round with jump offs not more than 10cms higher. But there may well be different heights for the various restricted competitions.
