In the add-page and edit-page forms, you can choose whether or not to use HTML tags. If you don't, your newlines will be preserved, but you get no other text formatting. The rest of this page applies if you check the "Use HTML tags and {} links" box in the forms.
You can use any HTML tags in your comments. In fact, if you *don't* want to use HTML, you need to type '<' instead of <, and '&' instead of &. You should also use '{' instead of {, because...
I've added a way to easily link to xenophilia pages. Suppose you wanted to point to the main humor page. The owner of that page is xenophilia; the page name is humor. You could write a link like,
<a href="http://www.xenophilia.org/sendpage.cgi/xenophilia/humor">Funnies</a>. Or, you can write this as {xenophilia humor Funnies}, and it will be converted when the page is delivered to the browser.
Funnies