When creating families, two ref planes always define the origin point of the family, which the user can set. The problem is, the only way to tell what is the origin is to select a ref plane, go to properties, and check the check box to see if its set to "Defines Origin".
My idea is that the origin ref planes should be identified differently, graphically. either the color is changed from the standard "ref plane green" to another color, or the linetype is different or fatter, or...something! Something to tell me these ref planes are "special".