Willy Bahuaud

This plugin goal is to prevent manual spammy links in comments.
<ol>
<li>It automatically remove links into comments, on articles posted more than than three months ago.</li>
<li>If someone want to post links in a comment, he must write fifty words to write one link, in the limitation of three links. Beyond, links will be automatically removed (and switched by the anchor links, without url scheme)</li>
</ol>
These moderation rules can be overrided in the Settings->Discussion screen of the admin dashboard.

Advanced Remove Links in Comments

Remove links in comments based on article publication date and comment length.

Arno Esterhuizen

When you add text to the category description textarea and save the category, WordPress runs content filters that strips out all but the most basic formatting tags.
This plugin disables those filters for roles with the necessary permissions. Any html code you add to the category description will not be stripped out.
This plugin does not do anything other than disable the filters. It does not protect you from entering invalid HTML, nor does it help you create WYSIWYG HTML. You can use the post or page composing screen to help you create the text and formatting. Switch to the ‘code’ tab and copy the HTML code into the category description field.

Allow HTML in Category Descriptions

Great Plugin

This plugin allows you to use unfiltered HTML in your category descriptions by disabling selected WordPress filters.

Advanced Remove Links in Comments vs Allow HTML in Category Descriptions