I ran a scan for Smarty variables in the Core that start with "$xoops_"

This is the list:

<{$xoops_avatar}>
<{$xoops_banner}>
<{$xoops_charset}>
<{$xoops_contents}>
<{$xoops_dirname}>
<{$xoops_footer}>
<{$xoops_imageurl}>
<{$xoops_isadmin}>
<{$xoops_isuser }>
<{$xoops_langcode}>
<{$xoops_logdump}>
<{$xoops_meta_author}>
<{$xoops_meta_copyright}>
<{$xoops_meta_description}>
<{$xoops_meta_keywords}>
<{$xoops_meta_rating}>
<{$xoops_meta_robots}>
<{$xoops_module_header}>
<{$xoops_name}>
<{$xoops_notification.redirect_script}>
<{$xoops_notification.show}>
<{$xoops_notification.target_page}>
<{$xoops_pagetitle}>
<{$xoops_requesturi}>
<{$xoops_sitename}>
<{$xoops_slogan}>
<{$xoops_themecss}>
<{$xoops_uname}>
<{$xoops_upload_url}>
<{$xoops_url}>
<{$xoops_userid}>
<{$xoops_version}>