To post a link in a message, enter the URL, including the leading http://. This will create a clickable link, for example:

http://www.cnn.com

Entering the URL without the http:// will not produce a clickable link.

Clickable text can be entered as follows:

[url=http://www.cnn.com]Go to CNN[/url]

This produces:

Go to CNN

Several alternate ways of entering URLs are shown in the pane to the right of the message window (when composing or editing a message).

For example, entering this:

[Go to CNN|http://www.cnn.com|Click here]

produces this (notice the "Click here" popup tooltip on the link):

Go to CNN