Some wikis define Automatic edit summaries, triggered by Mediawiki. They are apparently different from the tags.
English WIkipedia defines those AESs:
- Blanking a page
- Replacing entire page with other text
- Creating a new page (the first 200 characters of the article appear in the summary)
- Creating a redirect
- Reverting a revision
A filter for those special actions should be provided, as tags. (Original suggestion)