Content Syndication with RSS

Chapter 4. RSS 0.91 and 0.92 (Really Simple Syndication)

It’s so simple to be happy, but so difficult to be simple.

—Gururaj Ananda Yogi

In this chapter we examine the RSS 0.91, 0.92, and 2.0 specifications in detail. We also show how to create your own feeds and use those created by others.

RSS 0.91

The version documented in this section is based on the Userland document of April 2000 (currently found at http://backend.userland.com/rss091). Its author, Dave Winer, did not invent any new practices with this specification, but he did codify RSS in a far more precise way than the Netscape original (at http://my.netscape. com/publish/formats/rss-spec-0.91.html), based on common practice at the time. Primarily, the new codification imposed limits on the number of characters allowed within each element.

The only major difference between the Userland spec and the original Netscape write-up is that the Userland version lacks a document type definition (DTD) declaration. In fact, Netscape RSS 0.91 is the only RSS version with an official DTD, so most RSS parsers are used to dealing without one. Including the declaration is therefore a matter of personal preference (though it must be noted that useful character entities such as ™ cannot be used without it). Example 4-1 provides a DTD declaration for those who wish to use one.

Example 4-1. The top of an RSS 0.91 document, with a DTD declaration

<?xml version="1.0"?> <!DOCTYPE rss PUBLIC "-//Netscape Communications//DTD RSS 0.91//EN" ...