This info is now on TradGang in the How-To section. I TOTALLY agree with Brian. I maintain my Club's instructional bows and arrows. Every bow has a length marked on it. Some say AMO, some don't. Buying strings is a real PITA as some suppliers sell AMO-length strings, some sell loop-to-loop length. Note that the AMO length is totally independent of the length of a bow. It is the length of the proper string minus 3 inches. Why in the heck did they have to subtract 3 inches? While I can't, for the life of me, figure out why the AMO length was determined the way it was, at least it is a consistent reference.