On 3/15/2011 5:00 PM, Richard Light wrote: > In message<[email protected]>, Lee Passey > <[email protected]> writes > >> /No/ link is an identifier, except coincidentally. Whoever suggested >> that URLs could be identifiers, and that URIs should look like URLs but >> not be locaters should be scorned and ridiculed incessantly. > > That'll be Sir Tim BL, then, and the Linked Data principles? Or is it > just non-dereferenceable identifier URLs you hate?
If it's non-dereferenceable then it's not a URL. If it refers to an identifiable resource (verbatim copies of which may exist simultaneously at different locations on the internet), and there is an implied agreement that the identifier will be used exclusively and permanently to reference that resource, then it's a URI. A reference that meets the syntactical requirement of both systems is possible, and this is where we engender confusion. A reference may /look/ like a URL but not be one, because the web context has changed or it was never intended to be one in the first place. A reference may /look/ like a URI but not be one, because the resource pointed to may be in a constant state of flux, or be replaced on a regular basis (the URL of a blog is certainly not a URI of the content). If an identifier begins with an indicator of a web protocol (http:, ftp:, snmp:, nnp:, ldap:, etc.) I assume it is a URL, and because the internet is dynamic I will also assume that it is /not/ a URI because of the fluidity of the internet. I could be wrong on both points, but I have no way of knowing without trying. I have found only one way of determining whether an identifier is a URI: Google it, and see if anyone is talking about it as though it were a URI (not very amenable to automated data processes). What I hate is a system where an identifier cannot be distinguished between the two roles, leading even people like you to be confused about the two. Somewhere, someone took the notion of the Universal Resource Locator (as URLs were known in the Good Old Days) and said, "let's take the URL syntax and repurpose it to become Uniform Resource Identifiers. Sometimes a URI might be a URL, and that's close enough for government work." To misquote Garrison Keillor, "URLs and URIs are like the color green and the letter 'e'; sometimes you see a green 'e', but you learn not to expect it." _______________________________________________ Ol-discuss mailing list [email protected] http://mail.archive.org/cgi-bin/mailman/listinfo/ol-discuss To unsubscribe from this mailing list, send email to [email protected]
