I remain convinced of my capacity to harangue flag-happy officials (both when they are correct and when they've just cocked up another costly decision), to the point where they might occasionally favour the Arsenal just for a quiet life!
Source: wiktionary
Soccer players may "head" the ball for tactical purposes, while football players are barred from "leading" with their heads. Laving aside offensive and defensive lineman who do so every play. Also, most linebackers. A rule which is applied in practice only to defensive backs, arbitrarily, now and again, haphazardly, when a flag-happy zebra feels like it, but never to running backs who lower their heads to gain another two yards.
Source: wiktionary