One of the first things requested from a Drupal developer before contributing a module is to check whether the functionality is already implemented in another module. Because I couldn't find something similar but I do not feel confident that my search was conclusive let me explain what my Drupal warning module does.

The warning module was created as part of my war against comment spam. Mollom already does a tremendous job of blocking most of the comment spam (+-300 a day), but since my site was listed on do-follow lists I attracted a lot of spammers commenting (on-topic) on my articles as normal users, but leaving behind URLs to commercial and unrelated websites.

My blog is moderated since I don't want to encourage spammers anyway, but it is as important to clearly advertise that to anyone potentially adding spam.

For this reason a big warning box above the comment entry notifies the user that any effort spend would be in vain if they are to promote unrelated websites. And that the website is moderated anyway. The default message for the comment form currently is:

Warning Please refrain from adding URLs to unrelated or commercial websites. This site is moderated and comments with inappropriate links are rejected. Thank you for your understanding.

I used to get on average 10 to 15 spam comments with peaks of 30 spam comments. But since using this module for 5 days the average number of spam comments dropped instantly to 3. Some people apparently still do not take me serious :-)

The warning module could also be useful for other purposes since the warning message is configurable. And currently the module allows for 2 disclaimers: one for registering a new user and one for leaving a comment.

So if you want to test this module, you can find it for now at: http://svn.rpmforge.net/svn/trunk/tools/warning/

If you have suggestions or improvements, or you know another module that basically does the same, let me know. Also, this is my first Drupal module so any help with what I am doing is greatly appreciated.

Luckily it is a very simple module :-)

Update: The Warning module is now available from Drupal's Modules website at: http://drupal.org/project/warning