One of the things I like best about Atom so far is that it clearly separates a post summary, the thing that I choose to put in my RSS description element, from the full post content, which I choose to put in content:encoded. There are reasons to have both, there are people who want each, both within RSS-as-a-reading-format and in the wider view of syndication, and I want to be able to make it clear what I’m delivering to those in each camp.
However, Blogger’s peeing in my atom:summary already.
If you tell Blogger that you want an Atom feed with “Short Descriptions” it will publish you a feed with
<summary type="application/xhtml+xml" xml:base="http://foobazbar.blogspot.com" xml:lang="en-US" xml:space="preserve">
that is, XHTML where whitespace is significant. In that summary, it will put
the first paragraph, or approx. 255 characters, whichever is shorter of your post, with the (X)HTML stripped.
With the (X)HTML stripped.
If you start a post with
<ol> <li>Item one</li> <li>Item two</li> <li>Item three</li> </ol>
then the atom:summary in your Atom feed will contain
<div xmlns="http://www.w3.org/1999/xhtml"> Item one Item two Item three </div>
The idea of tagless “XHTML” with significant whitespace outside an element where whitespace is significant to XHTML (pre, script, style, and textarea, if my memory is right) is so utterly wrong that I see that even the (utterly wrong, for something which is of type application/atom+xml) CSSed display of it has no idea how to deal with such a beast.
If you want your summary to be application/xhtml+xml, then make it XHTML, whether you have to take the whole first block-level element, or chop it off in the middle of tags and then run that clobbered fragment through Tidy to make it something approximately valid. If you don’t want to put XHTML in it, make it text/plain, where a consumer will know that it needs to put in its own tags to hope to retain some semblance of the original sense (though you still will turn things which start with a blockquote into hopeless gibberish). But don’t tell me that plain text is application/xhtml+xml, while delivering an application as plain text. That’s not the Atom I was promised.