[jmillikin]

If I'm reading that page correctly, then abc.com is using User-Agent instead of Accept to determine whether the client supports XHTML. This seems like a really bad idea; what happens if (for example) someone uses user-agent spoofing to get desktop sites, and ABC serves up a mimetype that it can't handle?

Additionally, I'm baffled as to how any reputable site can actually serve invalid XHTML. The template engine should have logic similar to "if the client accepts XHTML, send XHTML, otherwise send HTML". To exhibit the behavior seen in this post, ABC's site must instead do something like "send the client HTML. if its user agent matches <regex>, claim you sent XHTML".

Somewhere in the bowels of ABC's IT department, there's a very confused intern with a copy of Web Programming for Dummies.

[PLejeck]

Even Web Programming For Dummies shouldn't suggest that. This is obviously the work of somebody reading a random $5 book from 2001, written by Newbie McRandomDude.