Perhaps so, but when you link to the W3C validation service it falls into the category of a "not recognised" browser when it connects to your page as you mentioned.

By using a simple bit of code in the page preInit you can remove it from the output and it caters for all browsers

Besides this may be an 'ancient' thread as you call it, by web standards it may be, but that's the nature of the beast, constant turmoil. Bit of chaos never hurt anybody:)