Blog

I’m always curious about names and where they come from and what they mean. Hence, my interest was aroused with the constant references to “XAP” in XMP. As the XMP Specification (Sept. 2005) says:

“NOTE: The string “XAP” or “xap” appears in some namespaces, keywords, and related names in this document and in stored XMP data. It reflects an early internal code name for XMP; the names have been preserved for compatibility purposes.”

Actually, it occurs in most of the core namespaces: XAP, rather than XMP.

(Continues.)

ACAP has released some documents outlining the use cases they will be testing and some proposed changes to the Robots Exclusion Protocol (REP) - both robots.txt and META tags. There are some very practical proposals here to improve search engine indexing. However, the only search engine publicly participating in the project is http://www.exalead.com/ (which according to Alexa attracted 0.0043% of global internet visits over the last three months). The main docs are “ACAP pilot Summary use cases being tested”, “ACAP Technical Framework - Robots Exclusion Protocol - strawman proposals Part 1”, “ACAP Technical Framework - Robots Exclusion Protocol - strawman proposals Part 2”, “ACAP Technical Framework - Usage Definitions - draft for pilot testing”.

A couple of recent posts - from A couple of recent posts - from at Jefferson University and IFST at Univ of Delaware- note that the AMA and APA style guides now recommend using a DOI, if one is assigned, in a journal article citation.

A citation in the APA style with a DOI would be:

Conley, D., Pfeiffera, K. M., & Velez, M. (2007). Explaining sibling differences in achievement and behavioral outcomes: The importance of within- and between-family factors. Social Science Research36(3), 1087-1104. doi:10.1016/j.ssresearch.2006.09.002

In the AMA style a reference would be:

Kitajima TS, Kawashima SA, Watanabe Y. The conserved kinetochore protein shugoshin protects centromeric cohesion during meiosis. Nature. 2004;427(6974):510-517. doi:10.1038/nature02312

This is great news. I haven’t looked at the full style guides but it’s not clear if information is given about linking DOIs via http://0-dx-doi-org.libus.csd.mu.edu/

Hadn’t really noticed before but was fairly gobsmacked by this notice I just saw on the DOI® Handbook: **Please note that Chapter 9, Operating Procedures is for Registration Agency personnel only.** DOI® Handbook doi:10.1000/182 http://0-www-doi-org.libus.csd.mu.edu/hb.html And, indeed, the Handbook’s TOC only reconfirms this: 9 Operating procedures* *The RA password is required for viewing Chapter 9. 9.1 Registering a DOI name with associated metadata 9.2 Prefix assignment 9.3 Transferring DOI names from one Registrant to another

Creative Commons now have a custom panel for adding CC licenses using Adobe apps - see here. Interesting on two counts: Machine readable licenses XMP metadata But I still think that batch solutions for adding XMP metadata are really required for publishing workflows. And ideally there should be support for adding arbitrary XMP packets if we’re going to have truly rich metadata. I rather fear the constraints that custom panels place upon the publisher.

Public comment period on the PRISM 2.0 draft ends Saturday (Sept. 15) ahead of next week’s WG meeting to review feedback and finalize the spec. (I put in some comments about XMP already. Hope they got that.)

(Update - 2007.09.15: Clean forgot to add in the rdf: namespace to the examples for xmp:Identifier in this post. I’ve now added in that namespace to the markup fragments listed. Also added in a comment here which shows the example in RDF/XML for those who may prefer that over RDF/N3.)

So, as a preliminary to reviewing how a fuller metadata description of a Crossref resource may best be fitted into an XMP packet for embedding into a PDF, let’s just consider how a DOI can be embedded into XMP. And since it’s so much clearer to read let’s just conduct this analysis using RDF/N3. (Life is too short to be spent reading RDF/XML or C++ code. :~)

(And further to Chris Shillum’s comment [(Update - 2007.09.15: Clean forgot to add in the rdf: namespace to the examples for xmp:Identifier in this post. I’ve now added in that namespace to the markup fragments listed. Also added in a comment here which shows the example in RDF/XML for those who may prefer that over RDF/N3.)

So, as a preliminary to reviewing how a fuller metadata description of a Crossref resource may best be fitted into an XMP packet for embedding into a PDF, let’s just consider how a DOI can be embedded into XMP. And since it’s so much clearer to read let’s just conduct this analysis using RDF/N3. (Life is too short to be spent reading RDF/XML or C++ code. :~)

(And further to Chris Shillum’s comment]2 on my earlier post Metadata in PDF: 2. Use Cases where he notes that Elsevier are looking to upgrade their markup of DOI in PDF to use XMP, I’m really hoping that Elsevier may have something to bring to the party and share with us. A consensus rendering of DOI within XMP is going to be of benefit to all.)

(Continues.)

You might have been wondering why I’ve been banging on about XMP here. Why the emphasis on one vendor technology on a blog focussed on an industry linking solution? Well, this post is an attempt to answer that.

Four years ago we at Nature Publishing Group, along with a select few early adopters, started up our RSS news feeds. We chose to use RSS 1.0 as the platform of choice which allowed us to embed a rich metadata term set using multiple schemas - especially Dublin Core and PRISM. We evangelized this much at the time and published documents on XML.com (Jul. ’03) and in D-Lib Magazine (Dec. ’04) as well as speaking about this at various meetings and blogging about it. Since that time many more publishers have come on board and now provide RSS routinely, many of them choosing to enrich their feeds with metadata.

Well, RSS can be seen in hindsight as being the First Wave of projecting a web presence beyond the content platform using standard markup formats. With this embedded metadata a publisher can expand their web footprint and allow users to link back to their content server.

Now, XMP with its potential for embedding metadata in rich media can be seen as a Second Wave. Media assets distributed over the network can now carry along their own metadata and identity which can be leveraged by third-party applications to provide interesting new functionalities and link-back capability. Again a projection of web presence.

(Continues.)

What on earth can this string mean: ‘W5M0MpCehiHzreSzNTczkc9d’? This occurs in the XMP packet header:

Well from the XMP Specification (September 2005) which is available here (PDF) there is this text:

“The required id attribute must follow begin. For all packets defined by this version of the syntax, the value of id is the following string: W5M0MpCehiHzreSzNTczkc9d”

(See: 3 XMP Storage Model / XMP Packet Wrapper / Header / Attribute: id)

OK, so it’s no big deal to cut and paste that string, it’s just mighty curious why this cryptic key is needed in an open specification, especially since (contrary to what might be implied by the text) it doesn’t seem to vary with version. (Or hasn’t yet, at any rate - more below.)

Following on from the missing XMP Specification version number discussed in the previous post here below are listed some miscellaneous gripes I’ve got with XMP (on what otherwise is a very promising technology). I would be more than happy to be proved wrong on any of these points.