I disagree; a "RESERVED for a private party" sign is effective even if you only understand the first word, and it's certainly not misleading.

Whereas a "RESERVED for fun and games" sign can easily confuse someone who understands the first word (perhaps they've seen it on other English signs before) but not "fun" nor "games", and they'll be misled into thinking they're not allowed to go into that area.

So if you were in a foreign land and knowing only a few words I saw a sign that said:

       CMWOHGHSJE!
         mvw pxx
     MVORUW the DUCKS

What would you think?