Wut? PHP hasn't a thing to do with .htaccess, the only thing that you *may* want to do is determine if mod_rewrite is in use and rewrite the links if you desire.
The receive page doesn't change. Mod rewrite links a url to a querystring, so the standard GET still applies to the script in use.
If you want to redesign the links, the very first step is adding an environment variable within .htaccess to declare that rewrite engine is on. Once that's complete, you can fetch that out of PHP and design your urls to match. For example:
if (isset($_SERVER['HASREWRITE'])) // Your environment variable
printf('Link: http://yoursite.com/article/%d', $articleid);
printf('Link: http://yoursite.com/article.php?articleid=%d', $articleid);
There is no automagic way to rewrite these, although use of an output buffer and replace may make it a lot easier so you don't have to manually write code like this. Becomes interesting though as you need a solid set of rules to work with.