PROPER vs UPPER vs LOWER: the three text-case functions

Three one-argument functions that reformat text case: UPPER shouts everything, LOWER quiets everything, and PROPER capitalizes the first letter of each word. The first two are foolproof; PROPER is the one that mangles names like McDonald and acronyms like NASA, so it needs a second look.

The differences at a glance

	PROPER	UPPER	LOWER
What it does	First letter of every word → capital	Every letter → capital	Every letter → lowercase
Example: "aDA loVELACE"	Ada Lovelace	ADA LOVELACE	ada lovelace
Typical use	Names, titles, place names	Codes, acronyms, headers	Emails, IDs, normalizing for match
Known gotcha	Breaks McDonald→Mcdonald, NASA→Nasa, o'brien→O'Brien wrongly	None	None
Digits & symbols	Unchanged (word boundary resets after them)	Unchanged	Unchanged
Compatibility	Universal	Universal	Universal — identical in every version we test

Which should you use?

UPPER — Standardizing codes, SKUs, state abbreviations, or headings where all-caps is intended. Also handy to force case-insensitive comparisons: UPPER(a)=UPPER(b).
LOWER — Normalizing emails, usernames or keys before matching/deduping, so 'Bob@X.com' and 'bob@x.com' line up.
PROPER — Tidying free-typed names and titles into title case — but review the output, since it capitalizes after every non-letter and won't respect McNames, acronyms, or particles like 'van'/'de'.

Compatibility (from executed tests)

All three execute identically across every version of all three apps we test — no dialect differences. The only real pitfall is PROPER's naive word-boundary rule: it capitalizes the letter after any non-letter character, so hyphenated and apostrophe names and embedded acronyms come out wrong and usually need a manual fix or a SUBSTITUTE pass afterward.

Example formulas

PROPER — title case	`=PROPER(A2)`
UPPER — all caps	`=UPPER(A2)`
LOWER — normalize an email for matching	`=LOWER(A2)`

Full per-version details on each function page: PROPER · UPPER · LOWER.