Re: Media Types URIs

Hi Jakub,

The comment for dct:format [1] reads “Examples of dimensions include size and duration. Recommended best practice is to use a controlled vocabulary such as the list of Internet Media Types [MIME]” so surely use of these URIs with it is appropriate? Perhaps more appropriate for general work than another list of file types due to the IANA list being very well known and widely used but not appropriate if specific file types are needed but not in the IANA list. The DCAT-AP list doesn’t look long, perhaps all its entries are in the IANA list? I could check this.

For dcat:mediaType (not dcat:mimeType!), I see that indeed the comment reads “This property SHOULD be used when the media type of the distribution is defined in IANA, otherwise dct:format MAY be used with different values” [2] so it would be appropriate and suggested to use these W3IDs for dcat:mediaType but I would add that, where possible if using dct:format, these W3ID Media Types too. In the ProfileDesc Ontology, as in many other places, dct:format is used and dcat:mediaType is not used so there I’ll be using these values.

Note that in the DCAT documentation, dcat:mediaType ise used like this:

dcat:mediaType "text/csv" ;

And I would prefer:


dcat:mediaType <https://w3id.org/mediatype/text/csv> ;

Regarding official use in DCAT: well let’s see! I like the idea of using most basic/widely understood and most widely accessible codelists so perhaps this list of Media Types now as LD is a challenge to the EU to step up their list accessibility!

Cheers,

Nick


[1] http://www.dublincore.org/documents/dcmi-terms/#terms-format

[2] https://www.w3.org/ns/dcat#



From: Jakub Klímek <jakub@jakubklimek.com>
Date: Tuesday, 19 June 2018 at 5:17 am
To: Nicholas Car <Nicholas.Car@csiro.au>
Cc: "public-dxwg-wg@w3.org" <public-dxwg-wg@w3.org>
Subject: Re: Media Types URIs

Dear Nick,

Are you suggesting using your IRIs such as [1] for MIME-Types with dct:format?

In DCAT-AP, dct:format is actually used with the EU File Type codelist [2] concepts such as [3], whereas for IANA based MIME Type IRIs such as [4], dcat:mimeType is used. Indeed, neither the File Type, nor the MIME Type IRIs are dereferencable. Still, some consistency would be nice.

BTW I have been asking the EU publications office to make the EU MDR NALs (now EU vocabularies) dereferencable for 3 years now, unfortunately with no success. Nevertheless, their use is mandatory in DCAT-AP, which could be reflected in DCAT since there are no other official code lists for those properties.

Best regards,

Jakub Klímek

[1] https://w3id.org/mediatype/text/turtle

[2] https://publications.europa.eu/en/web/eu-vocabularies/at-dataset/-/resource/dataset/file-type

[3] http://publications.europa.eu/resource/authority/file-type/RDF_TURTLE

[4] https://www.iana.org/assignments/media-types/text/turtle


On Mon, Jun 18, 2018 at 7:42 PM Car, Nicholas (L&W, Dutton Park) <Nicholas.Car@csiro.au> wrote:
Dear DXWG,

I’ve just put up a small API to deliver Media Types via URIs so if you want to quote text/html, you can do so like this: https://w3id.org/mediatype/text/turtle and get a simple web page or this:

@prefix dct: <http://purl.org/dc/terms/> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#<http://www.w3.org/2000/01/rdf-schema>> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#<http://www.w3.org/2001/XMLSchema>> .

<https://w3id.org/mediatype/text/turtle> a dct:FileFormat ;
    rdfs:label "turtle"^^xsd:string ;
    dct:contributor <https://w3id.org/mediatype/Eric_Prudhommeaux>,
        <https://w3id.org/mediatype/W3C> .

This just replaces a system that did this using purl.org/NET/mediatypes/<http://purl.org/NET/mediatypes/> but which has been down for years (see https://gist.github.com/stain/4635250).

The reason for doing this now is that we are really using dct:format a lot but don’t have dereferenceable URIs for it.
The register of Media Types is here: https://w3id.org/mediatype/


Consider this tool actively developed so you can raise issues (https://github.com/nicholascar/mediatypes-dataset/issues) or get things changed if they aren’t great!

Cheers,

Nick