How do I allow HTML for this?
 

<a href="http://i.imgur.com/dCJXFLv.png" target="_blank">http://i.imgur.com/dCJXFLv.png</a>

How do I allow HTML for each user to be used here and how do I increase the amount of characters that can be entered.

I highly recommend against allowing your users to embed HTML anywhere. You open yourself up to security risks otherwise. :D

Listen to this guy ^^ . Allowing your members to use HTML is a bad idea.

Well I could block the content of that with php anyway. Especially <script> and audio. iframe and <a> just a simple php check on the content of the field.

If my users want HTML markup in their user title (and I deem them worthy...:rolleyes:), I add it via the AdminCP myself. :D

But generally, I understand your point. Thanks.

The huge exercise in trying to tidy and sanitize html is not worth it to allow users arbitrary input.

What exactly is it that you want them to be able to do?

Another example of why you don't want to do this is I can simply input something such as '<a' or '<div ="' and it will break the whole forum.