[tdwg-guid] Is the http proxy of an LSID a GUID as well?

Ricardo Pereira ricardo at tdwg.org
Wed Jun 13 14:39:08 CEST 2007

    Hi Bob,

    Personally, I would hold on to pure LSIDs and avoid using the http 
proxy as a GUID as much as possible, just to make sure my clients are 
robust enough. However, the semantics of the proxy software and the RDF 
returned when the identifier is resolved allow clients to assume the 
http proxy is in fact a GUID.

    Below is an example of RDF that you get back when you resolve the 
proxy LSID.

  <rdf:Description rdf:about="urn:lsid:ubio.org:namebank:11815">
rdf:resource="http://lsid.tdwg.org/urn:lsid:ubio.org:namebank:11815" />

    In the case above, the LSID in its pure for is used as an identifier 
in *rdf:about* and *<dc:identifier>* (the namespace dc stands for Dublin 
Core.) However, the *<owl:sameAs>* statement asserts that both the LSID 
and its http proxy are equivalent and interchangeable. The proxy (the 
software at http://lsid.tdwg.org, for example) is the agent that 
actually implements that equivalence between the identifiers, without 
however asserting anything about resolvability of the proxied LSID. In 
my opinion, you can only assume that the proxy software will be able to 
resolve a given identifier as long as the proxy software itself and the 
LSID authority are operational. The proxy software cannot be deemed as 
an authority of that LSID. I think that this was your original concern, 
wasn't it?

    In summary, there is no problem assuming that a proxy version of an 
LSID is a GUID. But there are operational implications of using either 
form. It will all depend on whether the client is aware of  the LSID 
spec and its particular implementation. For example, if your client 
isn't aware of LSID spec, then you have no choice other than storing and 
using the proxy version to get back to the object associated with the 
ID. The client may use the pure LSID as a URI for internal calculations, 
such as graph merging and querying, but it won't be able to resolve it 

    On the other hand, if your client is aware of the LSID spec, you 
have more options. You know how to get from an LSID to a proxy version 
and back. You can use it in your advantage, or not. You may want to 
store both versions so that your client is more robust to link rot, and 
so on.



Bob Morris wrote:
 > Is the http proxy a GUID?

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