Pēc w3c specenes, XHTML dokumentam ir jāatgriež MIME type application/xhtml+xml. To dara sekojošs hederis:

Content-Type: application/xhtml+xml; charset=Windows-1257

Eksploreris pie šāda hedera nokristu (piedāvātu noseivot lapu), tad nu nācās skatīties, vai browseris akceptē šo MIME tipu.

<?php

if (stristr($_SERVER["HTTP_ACCEPT"], 

            'application/xhtml+xml')) {

  $header = 'Content-type: application/xhtml+xml;';

  $header .= ' charset=windows-1257';

} else {

  $header = 'Content-type: text/html';

}

header($header);

?>

Stilos biju paradis rakstīt tagus ar lielajiem burtiem. Nācās visu pārrakstīt ar mazajiem. Jo XML stilos tā jābūt... Ieskaitot to, ka nu jau BODY stils ir jānorāda arīdzan HTML elementam. Maģija.

Un kam tas viss nafig ir vajadzīgs?

While flattering, this is surely hyperbole. There are plenty who understand XHTML much better than I. And I don’t believe that people can’t do XHTML properly. Most people simply don’t need XHTML. So there’s no incentive for them to do it right.

If they use it anyway, it’s probably a matter of Geek-chic. Slapping an XHTML DOCTYPE on your weblog is like wearing sunglasses at night. It looks cool! But isn’t necessarily very functional.

Citāts no šejienes.