Hi Ben - you're not missing anything, the auto-define thing you mentioned would be a nice feature but for now it's either dynamic or predefined. Both have pros and cons, as you've seen. The nearest thing to what you're asking for is to fiddle with the collection XML. If you create a collection and define 2 fields in it, then cut and paste it into Notepad, you'll see how it works. Add a 3rd field line into the XML and paste everything back into the diagram - that should get you thinking. Not the most straight forward solution I grant you, but if you want to make up a 50 field collection, it can save a lot of time, especially if you use both Notepad and Excel formulas to make up the XML dynamically.