> In general, I think it would be a good idea to register some standard MIME
> Media Type "version" parameters. (Parameters are modifiers of the media
> subtype.)
This has to be done as part of the registration of the media type itself.
You cannot register a parameter separately; there is no process for it.
> Some RFCs mention this possibility; for example, in RFC 2045:
> In particular, some formats (such as application/postscript) have
> version numbering conventions that are internal to the media format.
> Where such conventions exist, MIME does nothing to supersede them. Where
> no such conventions exist, a MIME media type might use a "version"
> parameter in the content-type field if necessary.
Correct, and several media types have been registered that have such
parameters.
> I'm thinking of all the versions of PCL, for example: a particular Printer
> may support some subset of existing PCL versions.
The current registration of PCL, application/vnd.hp-pcl, doesn't have such a
parameter. The current change controller for this media type is HP; I suggest
contacting someone there if you want to amend the registration and add
such a parameter.
> Here is a made-up example of a MIME content type field using the version
> paramater:
> Content-type: text/line-data; charset=ibm500 (EBCDIC 500V1);
> version=ibm3800
Of course if you're registering such a media type yourself you can simply have
such a parameter as part of your registration. Make sure you completely specify
the syntax of the parameter value.
Ned