Never heard of 3/4 splice. Full-splice has always referred to the joint where the forearm meets the handle, etc, to the best of my knowledge. Lots of "full-splice" cues have butt sleeves slid onto a tenon below the wrap. Some folks even make their "full-splice" cues with one long tenon from the end of the points all the way to the butt. They slide the handle and butt sleeve onto it. Technically, since one piece of wood extends through the wrap area, they refer to it as full splice.
Joe