Every job needs a 'number' (which can contain letters, spaces and punctuation marks). If you already have job numbers, they'll work in the Tracker. If you're interested in integrating Tracker data with your accounting system, now or in the future, use the numbers in that system. But if you're creating new numbers ...
ADD, EDIT AND DELETE JOBS
ASSIGN ITEMS TO OR PURCHASE THEM FOR JOBS
Select the items you want to assign to or purchase for a job in the find and add to cart, fast add to cart or item assignments screen (the Assign to job and/or Purchase for job Tasks must be selected in the Preferences screen).
The Jobs table contains a large number of user-definable fields. All fields, whether user-definable or not, can be given custom names. So you may see a field in your Jobs screen that's not in this list: