Auto Increment / Identity Custom Field Type
I am currently implementing a system where there are user generated items, we can call them Orders. I would like to have a field (non-GUID) that is easy for customers to say over the phone or to write down that represents their order. The field should be simple and unique which made me think of an identity field. Can a portion of the item's GUID, say 10 characters, be unique enough? How can a unique field like this be implemented in Sitecore? GUIDs are alpha-numeric which is fine for my situation, but are too long. Currently I am doing so an example could be 103143317 (Store 103, at 2:33.17pm)