You are not limited by which world you are from, ex. if a canon, Naruto Uzumaki, wanted to deliver auto mail parts, he could. You must keep track of all job notes in your signature, including soul pills made, number of pizzas delivered, etc. If you don't, the number is automatically 0 until you put it in your signature.

If you have no space in your signature, contact an admin to see if something can be arranged. Until the ryo system is made, staff ask you to keep track of your ryo made from jobs in your signature as well.