Is there a fast-and-steady rule of which file extension (i.e. ".xhtml" or ".php") to use on a web page??
Obviously is all the code is XHTML then you use ".xhtml"
And if the code is all PHP, you use ".php"
But what if I have a Registration Form where 80-90% of the code is XHTML with just a little PHP sprinkled in??
(In therory, you could name any web page with some XHTML as ".xhtml" as long as you made sure to encapsulate your PHP as <?php .... ?> right?!)