Generally, the application data only contains information that is meaningful to the applications, since the control information in the message descriptor is sufficient.

一般地，应用程序数据仅包含对应用程序有意义的信息，因为消息描述符中的控制信息就已经足够了。

youdao

It identifies the message and contains control information, such as the type of message and its priority as assigned by the sending application.

它标识消息且包含控制信息，比如消息类型和由发送应用程序分配的优先级。

youdao

The header is used to pass control information, and the body contains the actual request or response message content.

头信息用于传送控制信息，主体包含实际请求或响应消息内容。

youdao

He says there is so much sensitive information elsewhere on the Internet -- in places such as message boards that companies can't control -- that the content at most company sites isn't that interesting to rivals.

CNN: Does your Web site reveal too much?

As the target is reading the message, malicious software they had inadvertently installed would report back to a command-and-control server, before collecting information from the phone.

FORBES: First-Known Targeted Malware Attack On Android Phones Steals Contacts And Text Messages