level is the level of like of manga. Blank = reads, ? = dosen't understand, 0 = dislikes, 1 = sometimes reads, 2 = moderate fan, 3 = definate fan, 4 = loves, N = Manga Otaku.
manga can make the template refer to a specific manga instead of being generic. (Note that in most cases, a specialized series template is better for this.), this defaults to manga and is completely optional.