[rfc-i] Unicode characters for ASCII control characters

Paul Hoffman paul.hoffman at vpnc.org
Wed Jun 3 10:06:57 PDT 2015

On Jun 3, 2015, at 9:54 AM, Nico Williams <nico at cryptonector.com> wrote:
> On Wed, Jun 03, 2015 at 12:33:33PM -0400, Phillip Hallam-Baker wrote:
>>> On 6/3/15 9:02 AM, Phillip Hallam-Baker wrote:
>>>> Does anyone know if there is a defined unicode character for
>>>> 'printable non-printable' ? I had a look and could not see
>>>> anything.
>> Found it! U+241E
>> I think this should allow a lot more useful examples when writing specs
>> with significant CRLF sequences.
> Very nice!

If we put the actual U+241E character in an RFC so that people can "see" the character, many people will copy-and-paste it into the programs, instead of using an U+001E character. I cannot imagine how you can word the surrounding text well enough to make it clear that you're just showing a character that you don't want them to copy-and-paste.

We have not heard any problems so far with people misunderstanding RFC 7464 and copying in the six characters "U+001E", or the four characters "001E", or even the two characters "RS". The proposal above seems likely to cause way more problems than it would fix.

If you absolutely need to indicate that character as a single unit among other characters, in the upcoming v3 RFC format, you can include SVG artwork, and that artwork can use a little picture for RS (and for LF, which is also useful for RFC 7464 examples). That artwork would be quite clear and no one would expect to be able to copy-and-paste from the artwork.

--Paul Hoffman

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