Quick Q&A time:
Note below that the Start Number, End Number, Last Number, and Warning Number are all required to be in a matching format: the same number of digits and prefix: (Not shown here: A series of numbering sequences (one per row) can also be set for various date cycles.)
The second part of this answer is also correct. Here is where you may specify the numbering sequence for the sundry AP documents:
Hope you enjoyed that, let us know any questions/comments below!