[Rfc-markdown] 1.6.31: <nobr> hack (non-breaking words)

[Carsten Bormann <[e-mail]>]

xml2rfc has some idiosyncratic rules on word breaking that have evolved over time.
See https://github.com/ietf-tools/xml2rfc/issues/984 for an example where the results hurt:

Check out lines 316 and 317 in:
https://www.ietf.org/archive/id/draft-ietf-lamps-header-protection-14.txt

Which are:

   Privacy and security issues regarding email Header Protection in S/
   MIME and PGP/MIME have been identified for some time.  Most current

This is definitely not what one wants xml2rfc to do here.
On the other hand, breaking on “/“ makes a lot of sense for most other usages.

Enter 1.6.31.  Just add anywhere:

*[S/MIME]: <nobr>
*[PGP/MIME]: <nobr>

Of course, there is no actual <nobr> in RFCXML yet, so this needs to be approximated using a hack involving Unicode word joiners (U+2060).

The advantage of this simple declaration is that you have to do it once and it will be taken care of everywhere.

The disadvantage is that all instances of S/MIME that might be subject to wrapping will now actually be S/<U+2060>MIME in XML and HTML (not in plaintext, where the word joiner is consumed in formatting).
This might impede searching for this term, if the search engine is naïve to word joiners.
This MUST disadvantage be fixed in RFCXML and is therefore out of scope for kramdown-rfc (which will happily adopt a <nobr> feature once it is implemented, keeping the same syntax of course).

Fine print:

Using <nobr> on an abbrev title by itself switches off any other functionality of abbrevs.
Additional text in the title such as:

*[PGP/MIME]: <nobr> #sec-pgp-mime

reinstitutes that.

Currently only spaces, hyphens, and slashes receive special treatment; this could be expanded to the fill list in

Grüße, Carsten

PS.: I made a dumb mistake in 1.6.30, which existed briefly; please use 1.6.31 if you picked up 1.6.30 by chance.