10 or more generic comments per day that are not in response to a question posed by the post or comment. “Thanks”, “Great Post!”, “Nice”, “Follow me”, etc
Commenting on old posts to hide self up-votes or a voting trail.
Copy/Paste comments that serve no purpose or the purpose is self promotion.
Comments that inform the contributor that they have been up upvoted, resteemed, or flagged when the curator does not actually upvote, resteem, or flag the post.
you should read @steemcleaners post, Abuse Guide - 2017 Update