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Re: Schemas using schemas.

From: Simon Cox <simon.cox@ned.dem.csiro.au>
Date: Thu, 24 Feb 2000 09:54:55 +0800
Message-ID: <38B48F6F.D4EB6421@ned.dem.csiro.au>
To: www-rdf-interest@w3.org
This approach is certainly not a problem for dc, since the DC definition explicitly 
states that in any description-instance all properties are optional.  

However, many schema's have more restricted obligations.  For example, in 
the ISO/TC 211 metadata standard (now defined in UML) they provide explicit 
instructions about how to create a custom "profile" of their base standard.  
The derived schema 
(i) inherits all mandatory components, plus non-mandatory ones as required, 
(ii) can increase the obligation, or restrict domains, and 
(iii) a single attachment point is provided for extensions.  
My interpretation of this is that they are requiring you to use the ISO 
schema as the "base" schema or not-at-all, and more or less prohibit you 
from extracting anything less than the complete thing for re-use.  

Pete Cliff wrote:
> I am developing an RDF schema for Collection Descriptions (call it
> rslpcld)  that is made up of a number of properties from a number of other
> schema - for example it is defined in terms of:
>   dc:title, dc:identifier, dcq:location, cld:strength, cld:accessControl,
>   vcard:voice, etc.
> but does not use ALL the attributes in any one schema.
> How do I define the namespaces in the rslpcld schema? My initial thought
> is to include a "xmlns:" line for each of the schemas used. However if
> this simply "#includes" the properties of other schema into the rslpcld
> schema then the rslpcld schema would be defined in terms of a number of
> undesirable properties.
Best			Simon
Received on Wednesday, 23 February 2000 20:58:51 UTC

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