En réponse à Philippe Caquant :

>I'm afraid I'm under 50 (so I hope to survive at least
>one more summer + winter). I can't remember where I
>heard this expression, I just know it. True, it is
>seldom used (or maybe locally ?) But many expressions
>seldom used can nevertheless be understood by a fair
>number of people. The proof is that you knew it too.
>Some can revive, too (let's save and recycle, as says
>our friend Czhang).

I knew it because I read it (only the expression, not the meaning of it. 
That was new for me) in a linguistic article about lexicon evolution as an 
example of a dead French expression. So it's not quite a common way of 
learning an expression, and it doesn't make me want to recycle it 
(especially since it's very insulting. Also, I lost my grandfather last 
November, so you can understand that the expression "passera pas l'hiver" 
is not very nice to hear). And as I said, no one in my surroundings 
(including people way above their 50s) knew the expression at all, not even 
in passive knowledge. So I can't believe in your "fair number of people". 
As I said, probably 95% of the population doesn't know what a PPH is, and 
the remaining 5% probably find the expression out-dated (like I do).

>"PPH" is on the same model as "BCBG" (which probably
>came later ?): "Bon Chic Bon Genre", also
>reinterpreted by "Beau Cul Belle Gueule". I think "P4"
>is also still understood, although military service
>has ended by now.

Never heard that one (and I am of the time when the military service still 
existed). Too bad for your "still understood". I know by experience that if 
I don't know an expression, nobody I know will know it either. I'm quite 
the collector.

>  It was a code used by the Army to
>indicate that somebody couldn't serve as a soldier
>because he hadn't all his wits (that's what the Army
>recrutor thought, of course).

Well, never heard that at least...

Christophe Grandsire.

You need a straight mind to invent a twisted conlang.