On Tue, 2006-09-05 at 15:53 -0700, James M Snell wrote: > Mike Linksvayer wrote: > > In any case, the draft says the referenced license only applies to feed > > or entry metadata, not content. This strikes me as not particularly > > useful and does not match analogous extentions for RSS 1.0 and RSS 2.0: > > The difference in semantics is precisely why I'm not using either the > RSS 1.0 or RSS 2.0 extensions for this as I see problems with both the > former approaches.
I understand having problems with RSS 1.0 and RSS 2.0 approaches but I don't see an inherent and important difference in semantics, particularly between Atom 1.0 and RSS 2.0. Of course my vision is probably foggy. :) > > http://web.resource.org/rss/1.0/modules/cc/ is RDF, so it is as clear as > > it can be what license annotations apply to, and in the examples they > > apply to the content at the feed (channel) URL (the feed itself) and the > > content at individual entry URLs (content of individual posts). > > It is helpful to take a look at the RSS 1.0 rdf:license definition. > > >From http://web.resource.org/rss/1.0/modules/cc/: > > <!-- start --> > This module aims to give metadata regarding the copyright license > under which the RSS feed, and the objects it points to, are released > under. > > [snip] > > <cc:license rdf:resource="URI OF LICENSE" /> > > <cc:license rdf:resource=""> can be a sub-element of an RSS item, > channel or image. The license it refers to is applied to the parent > element. As with any RDF elements, an occurance of <cc:license> within > any element implies the copyright of the document contained with the > rdf:about attribute of that parent element, and not the document > pointed to by the <link> sub-element. > > The element contains a single rdf:resource attribute which contains > the URI of the license applied. > <!-- end --> > > >From this description, and the example that is illustrated in > specification of the rdf:license module, it is evident to me, at least, > that rss 1.0 channels and items are licensed independently from one > another and that an item does not inherit the license of the channel, > otherwise, you could end up with significant problems if two feeds > referenced the same content item with two difference licenses, e.g. > > <rdf:RDF> > <channel rdf:about="http://example.org/feed1";> > <cc:license rdf:resource="http://example.org/license1"; /> > <items> > <rdf:Seq> > <rdf:li resource="http://blog.example.com/2006/08/foo"; /> > </rdf:Seq> > </items> > </channel> > <item rdf:about="http://blog.example.com/2006/08/foo";> > ... > </item> > </rdf:RDF> > > <rdf:RDF> > <channel rdf:about="http://example.org/feed2";> > <cc:license rdf:resource="http://example.org/license2"; /> > <items> > <rdf:Seq> > <rdf:li resource="http://blog.example.com/2006/08/foo"; /> > </rdf:Seq> > </items> > </channel> > <item rdf:about="http://blog.example.com/2006/08/foo";> > ... > </item> > </rdf:RDF> > > Because of RDF's data model and the definition of mod_cc, if licenses > are inherited by the items, these two feeds are either making > contradictory claims about the licensing of a single resource, neither > or which the channel publishers may actually have the right to license, > or they are claiming that the resource has been dual-licensed. > Unfortunately, neither claim can be substantiated by looking at the item > itself. > > Note that, because of the RDFs data model, the same problem occurs if > the items in each of the above channels each contain their own > contradictory cc:license links. > > Further, there is also the problem that the channel element is > describing a different resource that the item element. The definition > of cc:license says that the license applies to the parent element and > therefore the resource being described by the parent element. It is not > specified whether or not that license applies to other resources linked > to the channel. The subject of the channel is the feed itself, which necessarily includes any content delivered with the feed, including the full or excerpted text of individual items, if delivered with the feed itself. It is only in this sense that a feed level statement applies to item content -- when the content is part of the feed. > Also, there is a bug in the spec that, in certain situations causes the > spec to contradict itself. Consider the sentence: "an occurance of > <cc:license> within any element implies the copyright of the document > contained with the rdf:about attribute of that parent element, and not > the document pointed to by the <link> sub-element" then look at the > example given in the spec itself. > > <item rdf:about="http://c.moreover.com/click/here.pl?r123";> > <title>XML: A Disruptive Technology</title> > <link>http://c.moreover.com/click/here.pl?r123</link> > <cc:license rdf:resource="..." /> > </item> > > The link and the rdf:about attribute point to exactly the same resource, > making the assertion in the spec self-contradictory. The example could be more illustrative but it is hardly contradictory. AFAICT the item subject (specified by rdf:about) and the link property usually are the same, indeed the spec http://web.resource.org/rss/1.0/spec#s5.5 says they "should be identical ... if possible." I have no idea why the link property of an item even exists in RSS 1.0, but that's neither here nor there. > > http://backend.userland.com/creativeCommonsRssModule says license > > annotations apply to the "content of the RSS file" and "content of that > > item", mirroring the RSS 1.0 use. > > > > I do not believe that the RSS 2.0 definition mirrors the RSS 1.0 use. They look as close as they could be to me, given different models (URIs for feeds and items vs. "content of" feeds and items). Effectively they mean the same things. > I've already noted the problems with inherited licenses when > resyndicating entries in aggregated feeds. I agree that assuming entries inherit licenses specified at a feed level is problematic. My concern, at the feed and entry level, is that the atom license extension draft says that a link relation can (only) be used to associate a license with feed or entry metadata, rather than content. Unlike other children of <feed> and <entry> the license extension is not metadata for the feed or entry but metametadata for the feed or entry metadata, which strikes me as not particularly useful and contrary to both RSS 1.0 and RSS 2.0 modules, whatever differences exist between those. -- http://wiki.creativecommons.org/User:Mike_Linksvayer
