The proposal to revise the RSS specification has passed 5-1 with RSS Advisory Board members Matthew Bookspan, Rogers Cadenhead, Christopher Finke, Randy Charles Morin and Paul Querna voting in favor, Eric Lunt voting against and members James Holderness, Meg Hourihan, Jenny Levine and Jason Shellen abstaining.
The Extending RSS section of the specification has been clarified with the addition of the words "and attributes" twice in the following sentence:
A RSS feed may contain elements and attributes not described on this page, only if those elements and attributes are defined in a namespace.
No other changes were made. All edits to the specification are logged. This revision of the document has the version number 2.0.9.
In RSS Profile research, I analyzed how frequently RSS core elements and namespace elements appear in feeds.
Here's the compiled stats for item elements. Part one covered channel element usage.
The full report reveals that the most popular namespace element in RSS items is dc:creator from the Dublin Core namespace, which appeared in 42.7 percent of the feeds.
The second-most common is wfw:commentRss from the Well-Formed Web namespace, appearing in 34.3 percent. (This total includes wfw:commentRSS, a common miscapitalization of the element name.)
All core elements were found in at least 5 percent of the feeds surveyed with the exception of source, which appeared in 3.0 percent.
As part of the research for the RSS Profile, I compiled statistics on how frequently RSS core elements and namespace elements appear in feeds.
The full report reveals that the most popular namespace element is dc:language from the Dublin Core namespace, which appeared in 36 percent of the feeds.
The second-most common namespace element is atom:link from the Atom syndication format, appearing in 15 percent.
Four core elements were found in fewer than 1 percent of the feeds surveyed: textInput (0.31 percent), rating (0.26), skipDays (0.10) and the skipDays element day (also 0.10).
The following RSS Advisory Board proposal has been made by Randy Charles Morin and seconded by Rogers Cadenhead.
Under the advisory board charter, the board has seven days to discuss the proposal followed by seven days to vote on it. Interested parties can comment on the proposal on the mailing list RSS-Public.
Proposal
We'd like to propose a small clarification to the RSS 2.0 specification to remove uncertainty in the community over whether extension attributes are allowed to core RSS elements.
In the section Extending RSS, we propose that the following sentence be changed:
A RSS feed may contain elements not described on this page, only if those elements are defined in a namespace.
It should be revised to read as follows:
A RSS feed may contain elements and attributes not described on this page, only if those elements and attributes are defined in a namespace.
Rationale
When namespaces were added to RSS 2.0 by Dave Winer in 2002, he wrote on his weblog that he was deferring the details of their implementation to the Namespaces in XML specification:
I've added the section explaining how to extend RSS through namespaces. I'm basically telling you to ask the W3C how namespaces work, and do it the way they tell you to do it. I don't want to assume the problem of documenting namespaces in the RSS spec.
When namespace support was added, that version of the specification linked to a new RSS 2.0 sample file that used them. This sample file was part of the specification for the next two years.
The first line in the sample file makes use of a namespace attribute:
In the above, xmlns:blogChannel is a namespace attribute contained by the rss element that declares the blogChannel namespace.
The proposed spec revision makes it clear that this is valid RSS. If namespace attributes aren't valid RSS, every RSS feed that declares a namespace in the rss element is invalid.
Some namespace developers, most notably Microsoft, have employed namespace attributes on core elements.
To clear up confusion, support implementers who've emulated the specification, and give more clear guidance to namespace creators, this is an important and necessary clarification.
If you're interested in RSS but you don't know where to start learning about it, Lee and Sachi LeFever of The Common Craft Show have created RSS in Plain English, a breezy video that explains it in under four minutes.
