New Ways to Save a Quid
From Halopedia, the Halo wiki
New Ways to Save a Quid (or New Ways to Save a Buck on Steam) is an achievement in Halo: The Master Chief Collection. It is awarded for encountering a minor objective from Gunnery Sergeant Edward Buck on New Alexandria.
The player may not necessarily encounter Buck on a given playthrough. The level features three main objectives (Covenant communications jammers which must be neutralized by the player) which take place in a randomized order. Between each main objective, the player will encounter one of a handful of side objectives (two when playing three or four-player co-op). One of these is to escort Buck's Falcon from one part of the city to another for the purpose of Buck rescuing his men or carrying out a classified mission. If the player is lucky enough to encounter Buck, the achievement will unlock as soon as he radios the player requesting an escort.
On Xbox and Windows platforms the achievement may be called New Ways to Save a Quid in specific regions. "Quid" is slang for a pound sterling (GBP) in the same way that "Buck" is slang for a US dollar (USD).