Forum Module

The Forum Module is part of Drupal core. If you enable the Forum Module, there are some things to be aware of.

Whenever Web sites create tables that are sortable by column headers, you are looking at potential duplicate content.

Drupal's Forum Module

The image above shows table headers in Drupal's Forum Module. When you click on one of those links, it re-sorts the data in the table appending parameters to the original URL.

In the example image above, the original URL structure is http://example.com/forums/introduce-yourself. Drupal's Forum Module creates the following additional URLs in the header links:

Link Text URL
Title http://example.com/forums/introduce-yourself?sort=asc&order=Topic
Replies http://example.com/forums/introduce-yourself?sort=asc&order=Replies
Created http://example.com/forums/introduce-yourself?sort=asc&order=Created
Last Reply http://example.com/forums/introduce-yourself?sort=desc&order=Last+reply

After visiting those pages you (and spiders) will also find the following URLs:

Link Text URL
Title http://example.com/forums/introduce-yourself?sort=desc&order=Topic
Replies http://example.com/forums/introduce-yourself?sort=desc&order=Replies
Created http://example.com/forums/introduce-yourself?sort=desc&order=Created
Last Reply http://example.com/forums/introduce-yourself?sort=asc&order=Last+reply

Pagination of the forums makes it even worse because each page can then be sorted in these 8 ways. Here is one example from Drupal.org: http://drupal.org/forum/2?sort=asc&order=Last+reply&page=393.

SEO Recommendation for the Forum Module

The recommended fix for this problem is to add the following line to the robots.txt file:

Disallow: /*sort=

SEO Recommendations for Drupal Core

The following line should be added to the default Drupal robots.txt file because the Forum Module is distributed with Drupal:

Disallow: /*sort=

Module Information
Module Name:
Forum
SEO Issues:
This is a Drupal core module that comes with Drupal
CAUTION - this module needs configuration before using
This module may require a modification to robots.txt
This module has core SEO issues that should be repaired in future versions
Average: 4 (1 vote)

Comments

I agree - it's an SEO issue

I agree - it's an SEO issue and a performance issue. Having bots hit those pages all the time can be a resource drain on a server.

Have you submitted an issue and provided a patch to the core robots.txt? If not, please do.

Forum Module patch

I've been meaning to submit issues but have been busy getting this site online. The robots.txt tutorial describes a few issues with the default robots.txt.