Below is a formula for a quick and dirty autonumber for lists in SharePoint. There are a variety of ways to generate this field. Some solutions use workflow or external lists, but I prefer this method because of its simplicity.
Note: Because this solution depends on the record’s ID column, it generates the autonumber *after* a record has been added, so if you need the autonumber to appear in the “New..” form, this solution is not for you. My project, which required the Request Number to be in “WR-0000” format, was fine with having it generated after the fact.
To create my Request Number, I created a new calculated column, named it Request Number and entered the following formula:
This formula combines WR- with leading 0’s and the ID number that’s built into SharePoint lists. The output looks like so:
Thanks to my main SharePoint man, Trevor, for giving me this entire solution. You should start a blog, yo ;)