One was avoiding sending any substantial message at all when nothing had changed since the prior request.

其中之一是，如果自前一个请求发出以后内容没有发生任何改变，则避免发送任何实质性消息。

youdao

You might not have to risk your life any longer sending out one-handed Tweets on your Blackberry or iPhone, while trying to hide the fact that you are doing so under the dashboard.

你们也许不必再冒着生命危险来一边发送你的黑莓抑或iphone上单手完成的Tweets，一边尝试掩饰你正在仪表盘下干这些事。

youdao

This phase is the last one before the server actually starts sending content back to client, so it's the last opportunity modules have to made any tweaks or changes (hence the name of the phase).

这一阶段是服务器实际上开始发送内容返回到客户端前的最后阶段，这是模块必须做出任何调整或变更名称(因此阶段)的最后一次机会。

youdao