from the FAQS:

Links
[email] joe@email.com [/email] = Makes the given email address clickable.
[email: joe@email.com ] text [/email] = Makes the given email address clickable.
[url= link ] link [/url] = Makes the given url into a link.
[url= link ] title [/url] = Makes the given title into a hyperlink pointing to link.
[img] link [/img] = Embeds an image.

ergo:

[url= THIS IS WHERE THE HTTP STUFF GOES ]

formerly known as etaoin...