User blog comment:Eeepzlala/Urgent SBB levelling/@comment-108.230.185.124-20140913015207/@comment-202.156.15.42-20140913075858

Anything that adds effects are considered support. eg, Atk/Def/Rec/Crit/Hp/BB/Element/Status Negate. Just use any game knowledge you know. If the BB does damage, its always considered Offense regardless of whether it comes with other effects. If its a healing BB, its always considered Heal even if it gives a support buff. Just check the Unit guides in the wiki to know.