BUR #15988 has failed.
create implication head_wings -> wings
head_wings are wings.
...fine, I'll go into slightly more detail. Without this implication, post #6178074, post #6150802 and post #6138684 aren't tagged wings despite wings being a very prominent motif. Speaking of prominence, I've heard the argument that most head wings aren't "enough" to tag wings. I strongly disagree, but to play ball I would say mini_wings has the same issue, with posts like post #5147736 being tagged with it as a result of the already-existing implication. Again, that shouldn't be an issue; there's nothing wrong with that post being tagged wings.
However, even if you still think that's not enough, consider how keeping wings out of head_wings posts is already folly when users are justifiably adding demon_wings to post #6160188, or feathered_wings to post #6117188, or asymmetrical_wings to post #5634404 and so on. To keep these two tags separate we'd need to remove every implication to wings so that tagging specific kinds of head_wings wouldn't poison it. For extremely obvious reasons, that is a terrible "solution" that will never see the light of day.
Let's call a spade a spade and tag wings as wings.