It does say “shall remain quiet”, so there is no wiggle room. I would defer to my co-judge if I did not hear it for some reason.
1 - instructions to handlers
2 - who signals for birds
3 - who calls the dogs number
4 - each judge has liberty to say "no bird"
5 - every bird retrieved should be inspected (preferably by the judge not calling numbers)
6 - who gives instructions to handler if dog is to be picked up
7 - running or crippled birds - judges should decide in advanced how to deal with runners should problem arise
8 - judges should decide how to deal with encountering of wild birds
9 - agree in advance on creeping and if dog should be brought to heel before sending. (also in minor stakes, judges should agree about the degree of controlled break)