Question

In my site, I have used mod rewrite to make search engine and user friendly urls.

Only 3 rules:

RewriteRule ^articles/([a-z]+)/([0-9]+)/?$ /index.php?page=articles&cat=$1&id=$2 [L]
RewriteRule ^articles/([a-z]+)/?$ /index.php?page=articles&cat=$1 [L]
RewriteRule ^([a-z]+)/?$ /index.php?page=$1 [L]

But index.php is still accessible by anyone and will work even if a friendly URL is not used(that is, instead parameters are passed).
So, does this down rank by search engine ? Do I have to block direct access to files with .php extension ?

Answer 1

If you have 2 URLs that load the same page where one is search engine friendly and the other is not, this is not really detrimental to your site AFAIK. Basically you just want to expose to search engines as much as you can, so if you need to provide a parallel track, for example an anchor tag that works fine without Javascript because the action will take you to the correct place (which is ideal for a bot) but typically is managed by Javascript for clients that have it (most standard web browsers) then you’re golden.

EDIT:

Per OP question in a comment about parallel paths.. Say I have a link, an anchor tag.

<a id="moxune_services" href="http://moxune.com/services" action="get" target="_self">Moxune Services</a>

You can see that this is a valid link (and I will be getting SEO points for it from StackOverflow ;P But anyway, say this is part of a heave JS driven site, and rather than refreshing the whole page when this link is clicked, I just want to have a subsection of the page like where a div w/ id=”content” is present be replaced by the fresh content after I have AJAX load it. The js would be something like this (w/o testing, this is just off the top of my head) (a jQuery solution as well):

// very crude jQuery example!
$('#moxune_services').click(function() {
  $.get($(this).attr('href'), function(sNewHtml) {
    $('#content').replaceWith(sNewHtml);
  });
});

Now you see, the google bot can reach the page through the HTML a tag, no problem, but your customers looking for a Web 2.0 (TM) website will be able to enjoy the lack of full page refreshes as they have JS enabled (and hopefully aren’t using IE 6 :O).

One term for this is ‘graceful degradation’.