I am sorry if the control characters are actually super useful nowadays; I am not an electrician.

I am studying Unicode characters. More specifically, I am learning when and how to use them. But the control codepoints keep bugging me.

What are even contr...?

By "Control characters", I mean the set of valid ASCII/Unicode characters which do not render anything, but instead were (or are) used to control the host device.

So what?

Indeed, some control characters, like the Linefeed (LF) and Tab (HT) are still used today commonly for organizing text, but what about the others? Where can I use the Device Control 3 (DC3)? Can I even use the Negative Acknowledgment (NAK)?

It would be great if someone can write a detailed usage definition for each control character (If it is useful nowadays).


  • 2
    "I am not an electrician" - huh? What do electricians have to do with this?
    – gronostaj
    Nov 13, 2020 at 7:51
  • Might be better asked on retrocomputing.stackexchange.com Nov 13, 2020 at 8:06
  • Might be not better asked there: the question is clearly about contemporary usage. Nov 13, 2020 at 13:22


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