I was informed via Lynne Murphy of this map for an event held yesterday in Portland, Oregon.
The key at the bottom says that WC (British term for public lavatory, short for “water closet”) indicates “restrooms” (an American term for same), thus effecting a nice trans-Atlantic hybrid.
American WC tends to turn up in special circumstances, as in the Portland map, where the customary symbol for such facilities, a version of this–
–might end up too small to be legible. (Or maybe, Portland being Portland, the binary imagery was viewed as politically incorrect.)
The American company Kontextur uses the term for their range of bathroom-cleaning tools:
And it’s helpful in headlines, where space is at a premium. This 2004 New York Times article is about being stuck on a bathroom-less corporate jet:
WC is useful term, not only in being concise but in having a Goldilocksean just-right level of euphemism, not explicit about its function but, being willing to acknowledge “water,” nowhere near as opaque as “rest room” or “facilities.” I hope it catches on.
notoneoffbritishisms.com 
I thought WC was French for toilet (“double vey, say”), with the “water closet” being a back-constructed abbreviation.
https://www.collinsdictionary.com/dictionary/french-english/wc
I had always thought that the French use of ‘double-vey say’ was a construction from the English WC, but I have no evidence!
In view of the rareness of W in French (almost exclusively in non-native words), I am sure that you (Catherine) must be correct. What would it possibly stand for if it is supposed to be French?
I have never heard anyone in England call it a WC! The loo, the toilet, the ladies, the gents, the lav, but never the WC.
Brenda
It’s the same in Australia. ”WC” is only used in writing, mostly on florrplans or maps, exactly as it was used in the Portland example used here.
Incidentally, I was wondering recently about “loo”. Is it common in US English? I thought it was particularly British but I’m sure on a recent episode of the American TV series Charmed (the current reboot, not the version from 20 years ago) an American character in an American house asked three American sisters if she could use the loo. (Although one of the sisters is played by an English actress.)
The only other American usage of loo I could think of was in the Tom Lehrer song I Got if From Agnes which contains the line “It may have been in the pub or in the club or in the loo.” But that song was too naughty to appear on any of Lehrer’s early recordings and was revived for a British stage musical in 1980 so he may have re-written it for a British audience.
So, is loo a NOOB? When I was at school in the north of England in the sixties, I was often mocked for my London accent. When I used the word loo, somebody complained about me using these strange southern words.
Interesting, Paul. “Loo” is definitely not common in the U.S., but your examples suggest it may be a NOOB. I will look into it.
Turns out I wrote about loo in 2012: https://notoneoffbritishisms.com/2012/03/01/loo/
Interesting. I’ll have to listen out for more occurrences on US TV shows.
Lehrer said of the song in a 1996 interview: “I Got it From Agnes was written in 1952. Originally it was I Got it From Sally. I used to sing that in nightclubs, but I didn’t put it on records because I didn’t want to be identified with so-called ‘party records’ like those by Ruth Wallis, Rusty Warren, Redd Foxx. I didn’t want to be in that bin. When Cameron Mackintosh asked if there was anything else in the trunk that they could use for Tomfoolery, I polished it up, wrote a new verse, and made it more like a British music-hall song. Of course, that was all before anybody had heard of AIDS.”
I’ve been in old houses in England where the loo door has a little ceramic plaque with ‘WC’ on it. It’s also common in ‘estate agent’ speak of the more old-fashioned sort. So I don’t think it only means public toilet – it’s definitely in domestic use, though mostly by the older generations.
WC is used in continental Europe, but very rarely in the UK.
Brenda: have you never heard the old song that goes “Don’t use the WC when the train is standing in the station…”
It may be worth saying that what you call “the customary symbol for these facilities” is the customary symbol in Britain, too, although WC is sometimes used. Pointer signs in the street or within buildings may use the customary symbol or, frequently, the word “Toilets”. Signs in the street used to say “Public Conveniences” but this particular euphemism seems to have largely died out.
In America, “toilet” is thought to sound too explicit and functional.
Which is strange, because toilet is itself a polite euphemism, derived from the 18th century word for a room in which one washed or groomed oneself (if one was rich enough to have a special room for this).
I’m in Prague at the moment and plenty of signs around the place to WC. This afternoon I went up to Petrin Park and there were maps around the place of the type where places of interest were marked by numbers on the map and a key below said what the number means in Czech and English. Number 8 was explained to be a Czech word followed by WC and the English equivalent was given as Public Toilets.
Isn’t it in Lynne Murphy’s book where she describes an attendant at some tourist attraction in London not satisfied until he got an American tourist to ask for the toilet and not some other euphemism?
I just returned from my first-ever trip to England and as far as I can tell, the use of WC seems to be almost completely dead. Almost every sign I saw said “toilet.” In second place would be the male/female symbols (which seemed to look slightly different from the U.S. versions). I think I saw WC once.