RE: URI registries and schemes

Mike Schinkel writes:

> Similar, but not exactly the same. Google doesn't own the 
> physical world, but Linden Labs owns the virtual world in 
> Second Life.  So similar, but different.

I'd put it a bit differently.  Google has registered, and 
Linden Research has registered  That gives each of them the 
right to associate resources with http-scheme URIs for those domains, 
respectively.  So, if Google says that all URIs conforming to the template<lat>,<long> refer to the corresponding 
places on the physical earth, then they do.  If Google says that they 
refer to a set of Google map documents that happen to depict those places 
on the earth, then that's what they identify.  I suspect that for Google, 
it's the latter (to the extent they've been careful in documenting one or 
the other.)  The URIs don't really directly identify the place:  they 
identify Google maps of the places. says that URLs of the form<region>/<x-coordinate>/<y-coordinate>/<z-coordinate>/ 
"provides direct teleport links to locations in Second Life".  That's a 
bit informal, but it suggests to me that these links are documented by the 
responsible authority as referring not to a page or a document, but to a 
position in Second Life.  So, I think that's the difference.

BTW: there's a closely related discussion on the TAG mailing list which 
has to do with a related question: there's no question that if your URI 
identifies a document such as a map, an HTTP status code 200 is 
appropriate -- the question is, if your URI identifies something else, 
like a physical place or a person, is 200 still appropriate.  The TAG 
decided some time ago that the answer is "no", but the ramifications are 
still being (hotly) debated.  I strongly suggest we not run that debate in 
parallel here, but if you're interested (and have a few days free), you 
might want to go back through the archives of  Thanks!



Noah Mendelsohn 
IBM Corporation
One Rogers Street
Cambridge, MA 02142

Received on Monday, 17 December 2007 19:10:56 UTC