darrinb

Easily include raw markup languages (HTML, CSS, PHP, etc.) in comments using custom quicktags. No need to encode, the filter does it for you. Creates convenient “encode” buttons for comment authors in the HTML editor.
Also adds basic quicktag buttons on the comment forms, using the Quicktag API built into WordPress (as of 3.3).

WP Comment Encode

dubhunter

Spam is one of the most frustrating things about the internet. 
And, even more frustrating is how spiders scrape blogs and other sites for email addresses to spam. 
Wouldn’t it be nice if you could put mailto links just how you were taught, without fear of spiders? 
Well now you can! With this plugin, all mailto links will be filtered on display and converted to their unicode counterparts.

DBD Mailto Encoder

Spam is one of the most frustrating things about the internet.

WP Comment Encode vs DBD Mailto Encoder