The followings are the shapes of typical perforation belts. (Shape has been simplified. )
Ex1. Pin-feed hole (center) & Installation hole.
Ex.2 Pin-feed hole (both ends) & Insertion hole of work. 
Ex.3 Pin-feed holes (both ends) and sunction holes
Ex.4 Pin-feed holes (both ends) & Incision, bend, and standing of belt
Ex.5 Sanction holes (all over the belt)Title : Steel Belt (25) Shapes of typical perforation belts
