It's tricky. You use the "url tags" as usual, but you have to put the URL within the first pair of brackets, also inside quotes, thusly:
Typing
The link to this thread is {url="http://www.coincommunity.com/forum/topic.asp?TOPIC_ID=30570"}right here{/url}. (except using square brackets rather than squiggly ones) produces:
The link to this thread is
right here.
It can make it hard to read what you've actually typed, so hitting preview before hitting submit helps to check that it actually looks like you want it to look.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis