In response to user feedback, there are a few options that can be turned on, if you need them for your wiki. There is a Yada Wiki sub-menu under the main settings menu where you can enable comment options and set defaults for new wiki pages.
Yada Wiki does not support comments by default, but you can enable them if you want to allow comments on your wiki pages. If you want to enable comments, you need to check the first option, “Enable Comment Options”. You then have two additional options related to comments.
If you check the “On new wiki page: comments checked by default” option then comments will be enabled by default on new wiki pages. Otherwise, you can manually turn them on for each page on the editor screen.
If you check the “On new wiki page: trackbacks and pingbacks checked by default” then trackbacks and pingbacks will be enabled by default on new wiki pages.
The last optional setting, “Show Wiki Shortcode Buttons for Regular Posts and Pages”, will show the shortcode buttons for WikiLinks and the Wiki TOC on the editor screen for posts and pages, in addition to showing them on the wiki editor screen. This is a convenience to allow you to enter wiki links on posts and pages, but note that they wiki links must link to wiki pages, not regular posts and pages. See the FAQ entry about links for more information.