No snappy title about the Syrian cease-fire, but I’m glad that it’s happening

Exciting news from the Middle East: the cease-fire in Syria is mostly holding.  I wake up every day happy that I have food to eat and a job that I love–the people of Syria wake up happy that they’re still alive at all.  I hope that this keeps working.

• le cessez-le-feu: cease-fire.
• la trêve: truce.  Also a break, a let-up, or a rest, as in la trêve des confiseurs, the period around the end-of-year holidays when people bring treats to work.

Le cessez-le-feu is an interesting word, because it brings up the topic of nouns that come from verb phrases.  It’s quite common for nouns to be made from verbs.  For example, in English the verb imitate gives you imitation, create gives you creation, and so on.  It’s less common to see a noun that comes from an entire phrase.  You see these in French, though:

• le cessez-le-feu: cease-fire.
• le garde-à-vous: the position of attention (in the military).

There are lots of shorter ones, too:

• le porte-parole: spokesperson.
• le prête-nom: front man, figurehead.
• le rendez-vous: appointment, date, meeting place.

Are they all masculine nouns?  I don’t know–I don’t have a very big sample size.  Why are some formed from the vous form of the verb, and others not?  I don’t know.  Input from native speakers would be much appreciated!