Type -1: You've never skied before, you're over 50, and you've just had knee surgery. Your bindings will release if you sneeze.
Type 1: You've never skied before, or you're super-timid about this whole skiing thing still.
Type 2: You're starting to get the hang of this, and you want to explore the mountain a bit more.
Type 3: You're rocking blacks all day long, and would rather not spend your time digging for your ski in powder.
Type 3+: You want your leg to break before your bindings release.