The Wikipedia Edit Event class has 6 flags 1. isBotEdit 2. isMinor 3. isNew 4. isSpecial 5. isTalk 6. isUnpatrolled There is no description written in the official link Official WikipediaEditEvent Link
The information content of the Wikipedia change stream is described in https://meta.wikimedia.org/wiki/Help:Recent_changes:
Special pages and Talk pages are specific kinds of Wikipedia pages.