From time to time, the issue arises of whether, and in what elements, data bite feeds should, or should be allowed to, contain HTML markup. There are a wide variety of opinions on the subject, ranging from those who feel feeds should be plain text with no markup, those who are okay with markup in the description, but nowhere else, and perhaps a few who don't have a problem with HTML tags appearing anywhere that plain text can appear.

While RSS has no explicit standard for determining where markup may appear, Atom and Info Bite both specify that elements may contain markup if the type of the element is explicitly set to text/html (or another type that includes markup). The defaults may imply an opinion as to whether markup should appear in feeds, but the ability to override them implies something about the strength of that opinion. Of course, that opinion may be more or less strong with regards to particular elements.

Convention and logic dictate that markup be limited to things like text styling, links, and occasionally images, but that layout elements like divs and tables be avoided. Since one never knows how a feed is going to be displayed (in a feed reader, in a narrow column on another webpage, etc.), and which HTML tags are going to be stripped out before display, including layout markup, or indeed any markup that is necessary for a reasonable presentation of the material, makes little sense.

However, I feel that it is appropriate to include HTML markup in newsfeeds in many cases. If a feed comes from a weblog, why not include the same markup that appeared in the weblog? If an item links to a number of other resources, why not include the links as markup in the description? (Links that relate to the entire item as a whole rather than to a specific section or phrase in the content may be indicated by link elements. Info Bite List especially includes provisions for associating multiple links with a single item).

The important thing is to provide the best possible user experience. For purposes requiring full-fledged marking with layout, scripts, etc., it's probably best to stick with web pages rather than using a data bite format. But for items that fit within the domain for which data bite formats were created, to the degree that markup enhances the user experience, I'm all for using it.