Issue 552: Add URLs to official documentation

Starting Date: 
Working Group: 

Posted by George on 20/7/2021

Dear all,

Many people try to use the CIDOC CRM in order to build sustainable, reusable data sources and connect into a wider linked open data web.

When they do so, they would like to easily be able to find / use the URIs for the classes and properties that the standard declares.

The official documentation does not include this information in a handy way.

Proposal for discussion: include the URIs for the classes and properties as clickable links that resolve to the online space where they are maintained in the word/pdf specification.


Current Proposal: 

Posted by Robert Sanderson on 20/7/2021

Wholehearted agreement. Even if they're expressed in different ways by different representations of the conceptual model, if we can standardize the URI then an RDFS description and an OWL description of *the same URIs* can be used by different communities without breaking interoperability. If we get RDF*, or other declarative technological models for describing graph structures, then they too could describe the use of the URIs in their contexts.

Posted by Detlev Balzer on 20/7/2021

I'm one of those. 

The standard recipe would be to follow the linked data principles as explained e.g. in the . While the technical specs may look a bit intimidating at first, turning an RDF graph plus documentation into fully compliant linked data source requires only modest technical skills and effort. 

All the required pieces for URL routing come with commonly used web servers, and converting RDF on-the-fly into any desired format is handled out of the box by open source RDF stores such as RDF4J or Fuseki. Any aspiring young web programmer out there to take on the challenge?

Posted by Thanasis on 20/7/2021

I agree with this. Shouldn't it be part of the RDF implementation document? 

Posted by George on 26/7/2021

Dear all,

Thanks for your feedback on this. So it sounds like there is interest in discussing this as an issue in the next SIG. 

The proposal that was in my mind was that the specification document (the word/pdf) would also have the URL/I as a hotlink in the documentation of the class or property and that if you clicked this it would bring you to the server which would guide you to the definition of the class in some structured format be that RDFS or OWL or the detailed documentation format on the website: .

But there may be other perceptions or ideas around the best way of including this conveniently and where.

Posted by Nicola Carboni on 29/7/2021

Dear all,

Normally the link to the description already exists, but they only use property/classes number and they reflect CIDOC-CRM version 5.0.4

In fact, if you go to
you should be able to see an html version of the property description relative to P2 has type.

I noticed in the website that at the moment we can also point to the xml version of the documentation (which also use only property/classes number for the link). For example: points to the documentation of the property P2_has_type as described in version 7.1.1 of the documentation.

A simple solution would be to just redirect from the uri of a class/property to to the latest XML.
Example: should redirect to the property description in the last version available of the documentation ( Redirect should also be established for the property only present in RDF (e.g. P81a/P81b)

However, that opens up the problem of versioning. CIDOC-CRM in respect to many other ontologies is quite dynamic, so definitions changes and classes are added (or deleted) in time. The very first problem that come to mind is relative to the classes which have been deleted (e.g. Retrieve the scope note of E38 not knowing that it was deleted in version 6.2.9). However, even for the classes which have simply changed scope note, should we redirect to one specific version of the ontology (therefore reflecting the definition of that class in a specific moment in time when it was used) or simply point to the current one?

Because in case of the former solution, the namespace uri should include the version of CIDOC-CRM..