On Sat, Feb 08, 2014 at 08:55:02AM -0400, David Bremner wrote: > "W. Trevor King" <wking@tremily.us> writes: > > Rather than patching this in Emacs, maybe we should collapse the > > “not set” and “set to empty string” cases in notmuch-show.c? I > > can't think of any reasons why someone would want to distinguish > > those two cases, and it's easier all around if we standardize the > > representation as far upstream as possible. > > Do the RFCs have anything to say about headers with empty content? > If not I'd be inclined to leave the CLI output as raw as possible, > just because people are always finding new ways to apply tools. RFC 2183 does not describe Content-Description, it just uses it in some examples [1]. In all the examples where Content-Description is present, the value is not empty. RFC 2045 defines Content-Description, but it doesn't give all that much information [2]: The ability to associate some descriptive information with a given body is often desirable. For example, it may be useful to mark an "image" body as "a picture of the Space Shuttle Endeavor." Such text may be placed in the Content-Description header field. This header field is always optional. description := "Content-Description" ":" *text The description is presumed to be given in the US-ASCII character set, although the mechanism specified in RFC 2047 may be used for non-US-ASCII Content-Description values. I couldn't find more generic references to the meaning of empty header values, but I find it hard to imagine anyone assigning semantic value to an explicitly-empty description (vs. no Content-Description at all). Cheers, Trevor [1]: http://tools.ietf.org/html/rfc2183#section-3 [2]: http://tools.ietf.org/html/rfc2045#section-8 -- This email may be signed or encrypted with GnuPG (http://www.gnupg.org). For more information, see http://en.wikipedia.org/wiki/Pretty_Good_Privacy