The bulk update request #10267 has been approved by @nonamethanks.
create alias hair_bun -> single_hair_bun
create alias side_bun -> single_side_bun
remove alias hair_bun -> single_hair_bun
I was unaware that hair_bun was specifically only for single hair buns until I checked its wiki earlier today, and I'd wager I'm not alone in that ignorance. This should make it completely unambiguous.
However, I'm unsure what to do about hair_bun. Should we deprecate it, or turn it into a parent tag implicated by single_hair_bun, double_bun and so on?