Where can I get a list of all the "TAGS" available in xoops. By "TAGS" I mean things like {X_SITEURL}?

These are called "Smarties" and you can find info about them here:

http://xoops-tips.com/modules/news/article.php?storyid=12

This Q&A was found on XOOPS Web Application System : https://xoops.org/modules/smartfaq/faq.php?faqid=697