From auto- + numbering.
autonumbering (uncountable)
- (computing) Automatic numbering.
2001, Lisa Jahred, FrameMaker 6: Beyond the Basics, page 40:Luckily for us, that's where FrameMaker's autonumbering feature comes in. In documents, autonumbering does just what its name implies: It automatically numbers your paragraphs so you don't have to.