We're happy to announce another feature to assist with managing duplicate content: parameter handling. Parameter handling allows you to view which parameters Google believes should be ignored or not ignored at crawl time, and to overwrite our suggestions if necessary.

If you’re not handling this through robots.txt, this is a great way to simply address duplicate content issues cause by parameters leading to duplicate pages that display the exact same content.

The option in GWT indicates :

Dynamic parameters (for example, session IDs, source, or language) in your URLs can result in many different URLs all pointing to essentially the same content. For example, http://www.example.com/dresses?sid=12395923 might point to the same content as http://www.example.com/dresses. You can specify whether you want Google to ignore up to 15 specific parameters in your URL. This can result in more efficient crawling and fewer duplicate URLs, while helping to ensure that the information you need is preserved. (Note: While Google takes suggestions into account, we don't guarantee that we'll follow them in every case.)

Since someone emailed me to ask - here are some of my suggestions for optimal SEO configurations. If you have others – I’m interested.

Gallery2

• g2_highlightId : Ignore
• g2_imageViewsIndex : Ignore

Drupal

• destination
• order
• sort

Google Custom Search

• as_q
• sitesearch

BTW – Yahoo’s Site Explorer has had a similar concept with Dynamic URLs (under Actions) for years.

Specify up to 10 dynamic parameters that you want us to treat specially whenever these are seen in URLs belonging to http://www.yourdomain.org . We will automatically rewrite the URLs containing these parameters as specified below. You can choose to:

1. Remove these parameters from the URLs, such as in case of session ids, you could ask to remove 'sid' from URLs.

2. Use a default value for the parameter, for example you could set the 'src' parameter to be 'yhoo_srch'

I suggested the following fix, which I honestly don't remember where I got it from almost a year back when I was still using shared-host accounts, and it worked like a charm. Turns out, not very surprising, that the broken Gallery2 is related to changes done by the shared-hosting companies to better protect their servers. This specific problem has to do with PHPINFO settings, which Gallery2's mod-rewrite module is a bit sensitive about. Both bloggers found out that disabling mod-rewrite allows them to login, but that's not a solution. This next one is:

Add  the following lines in the .htaccess file (/making sure it's there):

RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*) index.php

Apply the following patch to the Gallery2 mod-rewrite module files :

file -- modules/rewrite/classes/parsers/pathinfo/PathInfoUrlGenerator.class
if (($pathInfo = GalleryUtilities::getServerVar('PATH_INFO')) -- before the changes
if (($pathInfo = GalleryUtilities::getServerVar('ORIG_PATH_INFO')) -- after the changes
file -- modules/core/classes/GalleryUrlGenerator.class
if (($tmp = GalleryUtilities::getServerVar('ORIG_PATH_INFO')) && $tmp != $path) { -- after the changes
if (($tmp = GalleryUtilities::getServerVar('PATH_INFO')) && $tmp != $path) { -- before the changes

Worked? great. Have a different solution? let me know...