When should I use "`" and "'" in NEWS?

[Xue Fuqiao <xfq.free@gmail.com>]

Hi list,

In etc/NEWS[fn:1], I found this sentence:

  You should either convert them to utf-8 or add an explicit coding:
  cookie.

I expected a "`" and a "'" around the "coding:" cookie, but there's
none.  So I have a question: when should we add these delimiters?  I
can't find a reference/convention documentation.

IMHO at least these things need those delimiters:
  * Lisp symbols
  * Configure options

and there are something I'm uncertain about:
  * Key sequences
  * Code span (I think "coding:" cookie is belong to this category)
  * "Modules" (like those in Eshell and Org)
  * Library/package names (with or without `.el')
  * Value of Lisp variables
  * Value returned by functions/lambda/primitives/macros

Footnotes:

[fn:1] http://bzr.savannah.gnu.org/lh/emacs/trunk/revision/112957

--
Best regards, Xue Fuqiao.
http://www.gnu.org/software/emacs/