- From: Andrew Daviel <andrew@andrew.triumf.ca>
- Date: Wed, 14 May 1997 18:29:34 -0700 (PDT)
- To: robots@mail.mccmedia.com, http-wg@cuckoo.hpl.hp.com, www-html@w3.org, meta2@mrrl.lut.ac.uk
I have submitted http://vancouver-webpages.com/ml/draft-daviel-metadata-link-00.txt which suggests a code of practice using Link relationships with existing HTTP/1.0 servers and HTML 2.0 parsers to associate metadata with non-HTML resources. I have tried to address most of the issues raised (apart from "forget it; it'll be in HTTP/1.2"). Basically, the concept is to include a Link header Link: <http://some.org/some-jpg.html>; rel="META" ; scheme="DC" in response to a request for a resource which cannot embed metadata with an optional reverse link Link: <http://some.org/some.jpg; rev="META" ; scheme="DC" from the metadata to the resource. Issues: Timeframe - Now. No server code or standards changes (but see scheme). Lying Metadata (spider bait) - Not addressed, same concerns as fulltext indexing (or using snowboarders to advertize beer). Metadata Spoofing - forward links given priority over reverse links. Metadata Structure - If a metadata format exists which does not support hyperlinks, it can be referenced using the HTTP header. Large Metadata - Only agents requiring metadata need request it. Agents need request only relevant metadata. HTML Equivalence - Since many authors have no access to HTTP headers, it is useful to define equivalent actions in HTML. Unfortunately, only the reverse link from HTML metadata or fulltext description to non-HTML resource is available. This causes problems of metadata spoofing, which may be solved simplistically by giving a higher priority to metadata whose URL best matches that of the resource. This is potentially a concern with other reverse link schemes such as DC.IDENTIFIER. Metadata encoding - The metadata is transported in its native 8-bit-clean format. There is no need to encode or encapsulate it. Multiple Schemes - It may be desirable to register a resource in more than one scheme. I suggest using an explicit scheme tag. Another possibility is to append the scheme to the relationship, e.g. REL="META.DC" Specifying an explicit scheme may break current HTML DTD. Compatability with future transport - nothing precludes making metadata available by other methods (GETMETA request, content negotiation, PICS), as they become more widely available. Why all these lists ? Well .. it's about metadata, it concerns indexing agents, and it uses HTTP headers. Apologies for duplicate mail. Andrew Daviel TRIUMF & Vancouver Webpages
Received on Wednesday, 14 May 1997 18:31:24 UTC