NOTE - In a previous draft, HTML included a <PLAINTEXT> element
that is similar to the <LISTING> element, except that there is no
closing tag: all characters after the <PLAINTEXT> start-tag are
Tim's post points to the impact of this virus:
His use of
<plaintext>, which turns out to be an obsolete HTML tag (I’d never seen it, and I’ve been doing this shit since 1994), has exploded Bloglines (no biggie, Bloglines is basically unmaintained these days) and demolished PlanetApache (scroll down a bit). PlanetJava has silent data loss, and del.icio.us is barfing angle-brackets.
Using deprecated tags to break numerous systems, reminds me of a principle Richard Thieme brought up at last year's Def Con which was that systems are built based on assumptions, but you cannot query the system about the assumptions it makes on your behalf.