This jacket is worked from the top down in Stockinette stitch with the collar worked separately in Trinity Stitch then attached by either a 3 needle bind off or grafting. Notations are included to make a shorter or longer body, a shorter or longer collar and either cap or 3/4 length sleeves. The longer collar is adjustable by buttoning one side underneath the other to create a fuller look. Though the body is worked in Stockinette it is worn as Reverse Stockinette.

I would rate this for an intermediate knitter.
The jacket pictured is a Large.