询问

The Enquiry symbol was designed for teletype and other communication systems. It was used to request a response from a remote device. As for communication protocols, the Enquiry symbol is applied to initiate data exchange by requesting confirmation to receive or deliver data.

The use of the U+0005 symbol has become less popular in modern computer systems and applications, since ts functions are often replaced by other communication methods and protocols such as TCP/IP, HTTP, and others.

Like other control characters, this symbol has no visual representation and doesn't occupy much space on screen or in typed text. There is a separate symbol in 控制图片  2400–243F . It represents a graphic image of the Enquiry symbol as the ENQ (Enquiry) abbreviation — ␅ .

符号 「询问」 包含在 「基本拉丁字母」 块的 「C0控制」 子块中，并在1993年作为Unicode版本1.1的一部分获得批准。