VIP

Status compressed into three letters, said one by one and readily placed before another noun: a VIP lounge is defined by who may enter it. The plural is a plain VIPs. The letters even stretch into a ladder. Don Thompson's The $12 Million Stuffed Shark (2010) has VIPs, VOPs and VVIPs admitted to London's Frieze Art Fair at different hours. Elsewhere the same letters name a gut hormone and a producer's own remix.

A biochemist's name for a hormone, and its expansion is a compact description: a peptide that is vasoactive, acting on blood vessels, at work in the intestine. As the name of a substance it usually goes without an article, as in levels of VIP or VIP in the bloodstream. For a general reader, spell it out on first mention.

A clinician's abbreviation, read straight off the hyphenated name: the ventilator does the inducing, and the pneumonia is the result. It behaves like other disease names. It is uncountable when it names the condition (patients develop VIP) and attributive in hospital reporting (VIP rates). It belongs to medicine and pathology, so in writing meant for patients the full form is the clearer choice.

Dance-music shorthand whose expansion few listeners know: variation in production. Ownership is what separates it from an ordinary remix. A VIP is the producer reworking a track of their own, not someone else's. It counts like any noun for a version, so a track can have a VIP, and an artist can play several VIPs in a set.