that's nice tomtom, I hadn't noticed to be honest, but you're right of course :-)

To be honest, I still don't get it.

You could read "in case of fire" as meaning "in case a fire starts" (because a fire might start). It would be an odd way to say it, though. Is that what you mean, tomtom?

As I read it, Do not use lift in case of fire means: Do not use the lift, because a fire could break out. This virtually means that you shouldn't use the lift at all.

If you turn the clauses around: In case of fire, do not use life, this tells you under which circumstances you shouldn't use the lift. If there's a fire, don't use the lift. If there's no fire, it's OK to use the lift.

#0 & 2
Neither do I. Am I now qualified to work in a hotel?!?

Wouldn't you say, though, that normally, "in case of X" means "if X happens", and if you mean "because X might happen" you use "in case X happens"? Even "Don't smoke in bed in case of fire!" still sounds like "Don't smoke in bed when there's a fire" to me.

Not to me; I think tomtom's right. Isn't

In case of fire,
do not use elevator

how the warning is usually posted in the US? In fact, it's so uniform that I suspect that the wording is set by OSHA or some other government agency.

In the UK it's "in the event of a fire" anyway, isn't it? Would avoid any misunderstanding.

Just find it hard to imagine a sentence where "in case of + noun" would mean "because (noun) might happen".
"I lock the door at night in case of a break-in?" Sounds odd to me - I'd say "I lock the door at night in case someone breaks in", for example. And UK websites with "in case of a break-in" all say things like "security systems that alert the security monitoring agency and police in case of a break-in", i.e. "if there's a break-in".

In deutschen Aufzügen ist meist ein Schild mit der Aufschrift: "Im Brandfall Aufzug nicht benutzen", doch welcher Ausländer weiß auf Anhieb, was mit "Brandfall" gemeint ist? Ein Freund hat vorgeschlagen, den Text des Schildes auch auf 'Ausländisch' zu präsentieren: "Wenn Feuer, nix Aufzug!"

"Es ist verboten, Personen in Aufzügen zu befördern, in denen das Befördern von Personen verboten ist."
Stand früher so in fast jedem Aufzug an der Wand.

#10 versteh ich nicht, was das heißen soll

#9 A picture might be more effective :-) Anything involving "fire" and "nicht" would serve as a decent reminder of what most people know anyway. I found "Ausländisch" much harder to understand than simple German back in the days when people tried it out on me.

Welche Firma hat den Lift denn gebaut? Hört sich nach einer Ingenieursübersetzung des deutschen Satzes an.

I think it is just wrong:
"in THE case of a fire" would be correct and is similar to "in the event of..."

(Hi Bluesky!)

#14 In BE it's "in case of", not "in the case of":

in case of
in the event of (a particular situation):
instructions about what to do in case of firehttp://oxforddictionaries.com/definition/case...

in case of something - used to describe what you should do in a particular situation, especially on official notices: In case of fire, break the glass.http://www.ldoceonline.com/dictionary/case_1

"In the case of" is slightly different; it means "when it comes to X":

in the case of sth/sb
with reference to someone or something, or in the situation of something
The law will apply equally to men and women except in the case of maternity leave.http://dictionary.cambridge.org/dictionary/br...

in the case of something
The amount of fruit in fruit juices must be 6% in the case of berries and 10% in the case of other fruits.http://www.ldoceonline.com/dictionary/case_1

In AE too, it's 'in the event of a fire,' but 'in case of fire.' Also in AE, signs should be as short and easy as possible.

I wonder whether usage of in case of/in the case of might not have changed in Britain. I also think I remember in the case of being used decades ago in the sense of in the event of, that is in the AE sense of in case of.

Now this somehow doesn't make sense. If I say: "Give me a plastic bag in case I'm sick", then I get the bag beforehand. If I get a bag in the event of me being sick, I get the bag during or when it is evident that there is a problem (sorry for the unsavoury example).

@SD3 - Maybe you are right about this being a BE/AE although I can't understand how "in case" could be understood in both meanings:
i.e. I'll make alternative travel arrangements in case you can't come to the party. 
-I'll make these arrangements anyway because it seems possible you may not come
and not
I'll make these arrangements in the event of you not coming to the party.
I think this is what the original question was about: Don't use the lift because there may possibly be a fire sometime, which does seem to be ambiguous (although everyone knows what is really meant).

@CM2DD #15: but according to your #8 we agree on this (???) (and I don't speak anything else other than BE)

Ich würde das Problem ja verstehen in einem Fall wie diesem: "Do not use lift to be safe in case of fire." Aber hier entsteht die Doppeldeutigkeit durch die unterschiedlichen Möglichkeiten zur Klammerung:
- (Do not use lift to be safe) in case of fire.
- Do not use lift (to be safe in case of fire).

Aber bei "Do not use lift in case of fire" kann ich das Problem ehrlich gesagt nicht nachvollziehen. Da Englisch nicht meine Muttersprache ist, hat das aber vermutlich nichts zu bedeuten...

Es handelt sich hier einfach um unterschiedliche Syntax, bzw. um die Betonung unterschiedlicher Aspekte.

M.W. gängig in BE (und auch in Australien) ist die von tomtom kritisierte Form, die primär ein Verbot ausspricht "Do not ...", gefolgt von einer Beschreibung der Umstände unter denen das Verbot gültig ist.

In AE wird hingegen zuerst eine Bedingung ausgesprochen "In Case of ... ", der dann eine Anweisung folgt; also im Prinzip eine "wenn-dann" Aussage.

OT: Ein klassischer/altbackener Scherz ist, wenn das Schild "Do not use lift in case of fire" mit einem handschriftlichen "use fire extinguisher instead" unterschrieben ist.

It should, as someone has said, be "in (the) event of" not "in case of", and I don't think the word order makes much if any difference.

"in case" = "lest", i.e. in order that... not.

"in case of" would be the prepositional equivalent.

Some may say this is pedantic, and in this example obviously we all know what is meant. But there could be other examples where it would not be so obvious.

It might be better to use a different (verbal) formulation: "Do not use the lift if there is a fire in the building."

Years ago on single-decker London buses there was a notice that said: "Smokers are requested to occupy rear seats". I remember having to ask what it meant. This was later changed to "Smokers are asked to sit at the back". A bit of thought can lead to clearer instructions.

@Henk L.
Benutzung des Aufzuges verboten, im Fall von Feuer

Die direkte Übersetzung macht das Problem auch in Deutsch klarer.

@traveler in time: Ich kann leider immer noch nicht nachvollziehen, was diese Formulierung anderes bedeuten könnte als "im Fall von Feuer: Benutzung des Aufzugs verboten". Kannst du es mir noch etwas genauer erklären, bitte?

#18 I was talking about the difference between "in case of" and "in the case of"; I would not use "in the case of a fire" on a sign as you suggested in #14.

To me it sounds like we are all talking about different things, though. Perhaps there are not just differences between AE and BE but also between the generations/regions - or perhaps we each just use a phrase a certain way as individuals and haven't consciously noticed that others use them differently.

I have no problem with the example in the ODE:

instructions about what to do in case of firehttp://oxforddictionaries.com/definition/case...

I see a difference in meaning between "in case of + noun" and "in case of + clause":

A. "in case of + noun" = if/when (after) (noun) happens (im Falle ...)
"Leave building in case of fire" = "leave building if a fire breaks out" (1. fire, 2. leave building)

B. "in case + clause" = because X might happen (für den Fall, dass...)
"Leave a spare key under the mat in case you forget yours" = "because you might forget yours" (1. leave key, 2. forget)

Am I right in thinking that some people understand "in case of + noun" to mean "because X might happen"?

Thank you everyone for your interesting contributions, particularly about the perceived difference between in case of and in the case of. Obviously, a lot of people don't see any problem with the wording. I still think, however, that simply changing the clauses around "In case of fire, do not use lift" (which takes up the same amount of space on a sign) would render it unambiguous. On the other hand, as has also been pointed out, everyone knows what it means anyway.

Wenn sich denn das Feuer dermassen schnell ausbreitet, dass man nur noch Zeit hat den halben sSatz zu lesen, dann ist man besser bedient mit "Lift nicht benutzen .../Dot use lift ...".
Waere "Lift must not be used ..." nicht eine kategorischere Anweisung?

No. 24 - Am I right in thinking that some people understand "in case of + noun" to mean "because X might happen"?

Yes, I think that's exactly the issue here. What about sentences like these?

Be sure to bring a jacket in case of inclement weather. ("in case it rains," or, as you say, because it might rain and you will want appropriate protection if it does)
Press red "emergency stop" button in case of emergency. ("in case there is an emergency")

The standard AE wording is indeed with "in case of fire" at the beginning of the sentence, which seems to make a difference to tomtom, but I don't think the difference is all that great. It's just a question of emphasis, setting up the condition in the reader's mind before the instructions so that he or she is primed to receive the instructions as intended, without having to think about it. You can still make that same joke from No. 20 even with the syntax switched around:

In case of fire(,) do not use elevator. (Scherzkeks: Use a fire extinguisher.)

Maybe that's why most signs I've seen in the U.S. actually say "In case of fire(,) do not use elevator. Use (the) stairs."

(The comma is frequently omitted because "in case of fire" is offset typographically – on its own line, in a larger font, boldface, etc.)

@ 21 - Really, you didn't understand the sign as it was? It sounds perfectly normal to me. But then, I'm American, and I'm used to people saying "vehicle" when they mean "car" and "gentleman" when they mean "guy."

@ 27

Not as an 8-year-old, I didn't. But my point was, why use language on notices that no one uses in real life?

Actually, I can understand why, in commercial contexts. The sign "Inexpensive garments for portly maturity" can be translated into "Cheap dresses for fat old women", and no one would buy them. But in other contexts, the use of obscure language is counter-productive.

I just checked the sign outside our elevators here at work (California, USA), and it seems that someone put some thought into the phrasing, because it tells people what to do in case of a fire, which in the case of an emergency is probably more useful than telling them what not do do:

"In case of fire, use staircase to exit. Do not use elevator."

@gnu (#11): Nun das Sprüchlein
"Es ist verboten, Personen in Aufzügen zu befördern, in denen das Befördern von Personen verboten ist."
soll heißen, dass man mit Aufzügen die nur zum Gütertransport bestimmt sind (z.B. Speiseaufzüge von der Großküche, Bettenaufzüge von der Bettenzentrale im Krankenhaus) keine Personen befördern darf. Eigentlich gar nicht so schwer zu verstehen.

Das hängt, wenn ich mich richtig erinnere, damit zusammen, dass die automatische Bremse bei nicht-Personenaufzügen anders/seltener/nicht(?) vom TÜV kontrolliert werden.

In BE, "in case it rains" means "because it might rain". "Bring a jacket in case it rains" means "It's not raining now, but bring a jacket, because it might rain later".

Equally, in BE, "in case there is an emergency" means "because there might be an emergency": "press the button in case there's an emergency" makes no sense, as it means "There's no emergency now, but press the button, because there might be one later".

"Press button in case of emergency", on the other hand, means "if there's an emergency, press the button". You see there's an emergency, so you press the button. It makes sense.

Equally, "bring a jacket in case of bad weather" means "if the weather is bad, bring a jacket". Again, you see the weather is bad, so you bring a jacket.

As I say, this is how I'd understand it in BE. Seems different in AE. Isn't it confusing to use "in case of" to mean two opposite things? ... If "(x)press button in case of (y)emergency" means that the (y)emergency happens first, therefore you (x)press the button, why doesn't "(x)bring jacket in case of (y)bad weather" mean the (y)bad weather happens first therefore (x)you bring the jacket? It would make sense, after all. Do you see what I mean?

Escoville, are you the founder of the Plain English campaign? :-) (I'm a fan!)

@CM2DD: Du schreibst im vierten Absatz: "Equally, 'bring a jacket in case of bad weather' means 'if the weather is bad, bring a jacket'. Again, you see the weather is bad, so you bring a jacket."

Dann schreibst du aber im fünften: "...why doesn't 'bring jacket in case of bad weather' mean the bad weather happens first therefore you bring the jacket?"

Da widersprichst du dich. Sollte es nicht heißen: "...why doesn't 'bring jacket in case of the weather is bad' mean the bad weather happens first therefore you bring the jacket?"

Wie dem auch sei: Ich finde diesen von dir in #24 beschriebenen Unterschied zwischen "in case of + noun" = "im Falle, dass" und "in case + clause" = "für den Fall, dass" auch höchst unlogisch.

#32 You didn't understand my point. It is complicated, but I didn't contradict myself, and I meant "in case of bad weather". ("In case of the weather is bad" wouldn't be correct English, btw - "in case of" has to be followed by a noun, not a new clause.)

Katydid said that in AE "bring a jacket in case of rain" means "bring a jacket because it might rain" (1. bring jacket, 2. perhaps rain)

But she also says that "press button in case of emergency" means "press button if there is an emergency" (1. emergency, 2 press button)

So Katydid is saying that "in case of" can mean both "if something happens" and "because something might happen". In the sentence you quoted I was expressing my surprise at the idea that one phrase could mean two so different things to her.

Ich finde diesen von dir in #24 beschriebenen Unterschied zwischen "in case of + noun" = "im Falle, dass" und "in case + clause" = "für den Fall, dass" auch höchst unlogisch.
Why? It's almost exactly the same construction as in German - or would you say that there's no difference between the two phrases in German? (Checked with my husband and he understands the phrases the way I do, is there a regional difference in DE too? :-o)
I'd say it makes at least as much sense for two different constructions to mean two things as it does for one construction to mean two opposing things, as it evidently does in AE.

FWIW the dictionaries agree with me...

in case (…)
because of the possibility of something happening
You'd better take the keys in case I'm out. 
in case of something(often on official notices) if something happens
In case of fire, ring the alarm bell.http://www.oxfordadvancedlearnersdictionary.c...

in case
as a provision against something happening or being true
 we put on thick jumpers, in case it was cold.
in case of in the event of (a particular situation)
instructions about what to do in case of fire.http://dws-sketch.uk.oup.com/cgi-bin/onlineOd...

CM2DD: Danke. Ich hatte das "of" nicht richtig beachtet und mich stattdessen nur auf den Teil, der danach kommt, fokussiert. Ich dachte deshalb, der Bedeutungsunterschied mache sich nur daran fest, ob man ein Substantiv oder einen ganzen Satz (mit Verb) verwendet. Das fand ich merkwürdig und unlogisch. Jetzt kann ich aber völlig nachvollziehen, was du gemeint hast, und die Sache ergibt endlich auch für mich einen gewissen Sinn ;-)

My explanation is a bit rubbish, though - this grammar book says it far better (the whole page is about "in case", and there's a comparison with "in case of" at the bottom): http://books.google.de/books?id=zxkBVphXuvsC...

CM2DD, I'm not saying that's how I'd express it – what I wanted to know with the sentence about "in case of inclement weather" is whether that sounded unnatural to you, or meant something different to you than what is intended. Evidently it does. (I personally would still say "in case it rains" or "in case we run into bad weather" in, ah, the case of multiple possible kinds of bad weather.) I think this is an area in which there is – and has been for many years – so much inexact usage that in practice, the two can be functionally equivalent.

Hmm, maybe I'm actually back to the issue of syntax that tomtom was talking about, after all: I would be hard pressed to understand the sentence with "in case of inclement weather" at the end as meaning "if you see that it's already raining, bring a jacket." If you wanted to express that in the same words, I'd put the "in case of" part at the beginning. Interestingly, I have no problem correctly construing the conditional sense of an "if" clause in a sentence such as "bring a jacket if it's raining," despite having to wait for it.

Fowler (revised 3rd) says: "In AmE, in case can also mean 'if': In case it rains I can't go (= If it should rain)," and he lumps together "in case (of)" as a single phrase meaning both "in the event (that)" and "supposing (that)" – which to me sounds an awful lot like the two meanings you – and the grammar books – are hearing as distinct, with "in case" meaning "against the eventuality that X might happen" and "in case of" meaning "if or when X actually does happen."

Garner, in Modern American Usage (2003), is forceful in inveighing against "in case (better made if), (...) in the case of (usually best deleted or reduced to in)" as "flabby," based in part on an earlier edition of Fowler. He doesn't mention "in case of" as such.