Re: [Yaml-core] MIME type

[why t. l. s. <yam...@wh...>]

Nathan Sharfi (nis...@ts...) wrote:
> I'd recommend against text/yaml because it's not officially registered through the
> official MIME registry, and prefer text/x-yaml in the interim...of possibly several
> years, if nobody cares enough to fill out the paperwork to add it.

Yeah, possibly.  I read a couple RFCs on the matter tonight and scoured
some MIME sites and none seem to indicate that use of 'text/yaml' would
be a problem.

From RFC2046, Experimental Types section:

   A media type value beginning with the characters "X-" is a private
   value, to be used by consenting systems by mutual agreement.  Any
   format without a rigorous and public definition must be named with an
   "X-" prefix, and publicly specified values shall never begin with
   "X-".  (Older versions of the widely used Andrew system use the "X-
   BE2" name, so new systems should probably choose a different name.)
   
   In general, the use of "X-" top-level types is strongly discouraged.
   Implementors should invent subtypes of the existing types whenever
   possible. In many cases, a subtype of "application" will be more
   appropriate than a new top-level type.

The 'text/yaml' MIME is a subtype of 'text'.

From RFC2048:

   2.1.4.  Special `x.' Tree
      
      For convenience and symmetry with this registration scheme, media
      type names with "x." as the first facet may be used for the same
      purposes for which names starting in "x-" are normally used.  These
      types are unregistered, experimental, and should be used only with
      the active agreement of the parties exchanging them.
      
    > However, with the simplified registration procedures described above
    > for vendor and personal trees, it should rarely, if ever, be
    > necessary to use unregistered experimental types, and as such use of
    > both "x-" and "x." forms is discouraged.

From what I can glean from official documents, stuff like the "x-"
prefix is generally used for private, ad-hoc formats.  Not for publicly
documented and well-documented formats like YAML.

> For what it's worth, most of the newer, more specific XHTML media types are being
> served up in the application/* tree, most notably application/xhtml+xml (the
> preferred MIMEtype for XHTML 1.1 documents).

That MIME type is quite indicative of the entire standardization process
I see in the XML community.  YAML is simple.  After reading the MIME
RFCs, I'd say generally we'd encourage 'text/yaml'.  Perhaps there will
come a need for an 'application' subtype.  I'd say it's worth
registering a media type soon, though.  I currently use YAML frequently
in HTTP and email communications.

_why