The original rules here were, no whistling because the pickpockets will whistle signals to one another.

最初这儿的规则是禁止吹哨，因为扒手会给另一个同伙吹信号。

The whistle signalled the end of the match.

【signal】哨声吹响，示意比赛结束。

A vessel aground may in addition sound an appropriate whistle signal.

搁浅的船只还可以发出适当的汽笛信号。