One of the things I have been struggling with in Operator is whether or not to allow for invalid microformats when I can detect the problem and fix it. After much soul searching, I have decided the answer is no. And I will take this opportunity to discuss in particular the tag problems I have found.
The culprits I have found mainly seem to be blog apps. Take my blog for instance, which uses Blogger. If you are using Operator 0.5, you'll see that the tags for this page are "firefox.html," "operator.html" and "microformats.html." All invalid. In the source of the page, you will see this:
<a rel='tag' href="http://www.kaply.com/weblog/labels/firefox.html">firefox</a>
The problem is that blogger is believing that the tag is the textContent of the anchor, not the last segment of the URL. To quote the rel-tag specification:
the last segment of the path portion of the URI (after the final "/" character) contains the tag value
WordPress also has a problem which can be seen at http://microformatique.com/ if you turn on debug mode in Operator.
So what is my plan then? I'm going to work on the detection in Operator to find the invalid rel-tags and simply not display them.
And hopefully some developers will go fix their implementations.