Do you mean where it's like
this instead of this:
http://forums.uesp.net/viewtopic.php?t=13197
If so, just type the word or words you want, highlight them, and click the URL button in the top right below the subject box it will come up with [url]word/s[/url]. Then just put an = sign after the first url (inside the brackets) and copy the link. It will look something like this: [url=something.com]word/s[/url] and when posted will look like
word/s.