html and xhtml are "standards" just like the centimeter or inch, you can "measure" anything using them! still, complying standards is more like FOSS way of life, you should -in most cases- find the validation page of (x)html and\or CSS in all FOSS activists websites, it helps making the web better..
------------------------- Ahmed Faissl twitter: @faissl website: www.aldarweesh.org Goes without saying..

