Unicode "no-op" Character?

J Decker via Unicode unicode at unicode.org
Sat Jun 22 16:19:14 CDT 2019

On Sat, Jun 22, 2019 at 2:04 PM Sławomir Osipiuk via Unicode <
unicode at unicode.org> wrote:

> I see there is no such character, which I pretty much expected after
> Google didn’t help.
> The original problem I had was solved long ago but the recent article
> about watermarking reminded me of it, and my question was mostly out of
> curiosity. The task wasn’t, strictly speaking, about “padding”, but about
> marking – injecting “flag” characters at arbitrary points in a string
> without affecting the resulting visible text. I think we ended up using
> ESC, which is a dumb choice in retrospect, though the whole approach was a
> bit of a hack anyway and the process it was for isn’t being used anymore.

The spec would suggest that there are escape codes like that, which can be
APC, <Application Program Command>  U+009F
ST, String Terminator, U+009C
which is supposed to be a sequence of characters that should not be
displayed, but may be used to control the application displaying them.
(assuming they understand them)


156$9CSTString Terminator 234 9/12 ST
ESC \ Closes a string opened by APC, DCS, OSC, PM or SOS.

159$9FAPCApplication Program Command 237 9/15 AC
ESC _ Starts an application program command string. ST will end the
command. The interpretation of the command is subject to the program in
But it doesn't appear anything actually 'supports' that.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://unicode.org/pipermail/unicode/attachments/20190622/3f185e48/attachment.html>

More information about the Unicode mailing list