Code:
<xen:container var="$head.canonical"><link rel="canonical" href="{xen:link 'canonical:index'}" /></xen:container>
Above code is taken from: acp->appearance->templates->forum_list.
Questions:
1. how could I know what is the container of forum_list?
2. xen:link, where can I see the syntax of xen:link? I can see xen:container here: http://xenforo.com/community/threads/xenforo-template-syntax.23245/, but can not find xen:link
3. what is canonical?