Hello,

I have two question regarding encoding schemes and rich representations.

1. "Each value string may have either an associated syntax encoding scheme
URI that identifies a syntax encoding scheme or an associated value string
language that is an ISO language tag (for example en-GB) but not both."

I am wondering why you exclude encoding scheme plus language tag. I am
thinking of the German version of the DDC, which is under development by the
German National Library. Wouldn't it be appropriate to declare these values
as 

      VocabularyEncodingSchemeURI ( dcterms:DDC )
	Language ( de-DE )

Or do you rather envision an extension of the EncodingSchemeURI
(dcterms:DDC/DE or something like that)?

By the way, for the processing of metadata, the difference between notation
and label might be important: Nobody outside the Mathematics community will
find the value "15A09" very useful (unless there is a resolution mechanism
available somehow), but "Matrix inversion, generalized inverses" could be
meaningful in a general context. Is there a way to differentiate between
these, again probably by extending the VocabularyEncodingSchemeURI?
(My understanding is that the licensing model of DDC usually will not allow
the presentation of both.)

2. I find it very useful that
"Each rich representation must have an associated media type (a MIME Media
Type)."
While really not the fault of DCMI, the usefulness of this is somewhat
limited by the MIME types and their administration (cf.
http://tools.ietf.org/html/rfc4288).
This is essentially a question regarding the encoding scheme
http://purl.org/dc/terms/IMT and its use in this context.

- I would like to use TeX in a rich representation
  (even in mathematical titles there may be formulas best expressed in TeX),
  but there is no MIME type for TeX or LaTeX
  (text/vnd.latex-z is something very special).
Should I use application/x-latex, which is not registered with IANA, but in
common use?

- The other interesting case is Rich Text Format.
  For RTF there are *two* MIME types:
application/rtf	http://www.iana.org/assignments/media-types/application/rtf
text/rtf		http://www.iana.org/assignments/media-types/text/rtf
  The first link results in a 404 error, the second refers for the
  specification to a server no longer existing.
  Is either of them the RTF understood by almost all word processors?

("A precise and openly available specification of the format of each media
type MUST exist for all types registered in the standards tree and MUST at a
minimum be referenced by, if it isn't actually included in, the media type
registration proposal itself." RFC 4288)

So how do I proceed with my rich representation values?
Contact IANA and register the appropriate type?
Use text/rtf regardless? Or the unregistered application/x-rtf or
text/x-rtf?

Greetings
Thomas

– –
Dr. Thomas Fischer
Metadata and Databases
Göttingen State and University Library
37070 Göttingen
Germany
Tel.: +49 551 393883
and   +43 662 621498