if it's yellow, let it mellow; if it's brown, flush it down

== English == === Etymology === Initially coined during one of the California droughts. (This etymology is missing or incomplete. Please add to it, or discuss it at the Etymology scriptorium.) === Phrase === if it's yellow, let it mellow; if it's brown, flush it down In order to save water, only flush the toilet after defecation, not after urination.