I have noticed some footprints have "no comments" or "comments closed". Why would you search for blogs where you cannot comment or comments are closed? I'm sure there is a very clever reason for it!
I see the reason for "no comments" as it may come from "No comments yet.Be the first to comment". So it may be useful for people that want to comment on low outbound link sites. but I cant figure out the logic for "comments closed".
comments may be closed but often the site owner has forgotten to close trackbacks too, so this can be a way to find sites that have allowed comments, have closed them, but are still allowing trackbacks ...