To do this task
Go to the Lists menu, choose Customer & Vendor Profile Lists, and then
click Job Type List.
Click Job Type at the bottom of the list and click New.
Enter the job type as you would like it to appear on the Job Type list.
(Optional) If you want the job type to be a subtype of another job type,
click the Subtype of checkbox and choose the job type that will be
the "parent" from the drop-down list.
Why use subtypes?
About job types
Change information about job
Make a job type