“WRAS approved” is on nearly every UK plumbing spec sheet, but what does it actually certify — and can you legally use something that isn't? Here's what the badge means, and doesn't.

ACOP L8 and HSG274 both come up in every Legionella conversation, but they aren't the same document and don't carry the same legal weight. Here's what each one actually requires — and where showers fit in.