Talk page
Talk page is the concept of having a parallel page for each wiki page to handle discussions about that page.
That can somewhat be done manually in Tiki (just create a page and link to it). However, it's more typical to use Comments at the bottom of the page, or to insert the notes in the page and hidingfrom some people and/or clearly indicating the nature of the text (ex.: non-official comment) using PluginGroup, PluginQuote, PluginMouseOver, etc.
Related links
http://meta.wikimedia.org/wiki/Help:Talk_page