There is a feature to Report File by clicking the flag icon next to the filename. It sends a message ("Content flagged as objectionable") from Groups.io to each owner/moderator.
We recently saw a file reported this way, because someone had a question about the file. The right thing for him to have done, was to send a new Message. But he saw the flag icon and used it.
1. When someone reports a file, Groups.io sends messages addressed to each Owner/Moderator. I think it should be addressed to the "+owner" address. By addressing it to Owner/Moderator addresses, it looks like Spam. (Indeed, my co-moderator interpreted it that way, especially because the sender's status was NMM.)
2. It leaves nothing behind in the group's "Activity" log. Nor in the sender's "Activity History". Nor in the sender's "+owner Messages". It should. All three.
3. When reporting a file, the description in the pop-up window is: "I think this file isn't appropriate for our Group." Hmm. I was thinking that is much too open-ended. It's not the same thing as "objectionable". But maybe that was your idea, to allow it to be used for any reason, leaving discretion to Moderators. Yes? Still, I wonder if it should be for things actually bad and objectionable. I'm also wondering, because we have many group members not in the USA for whom English is not their native language.
Also, while the following is not about "Report File", it is related to #2 above:
2A. If an Owner/Moderator sends a follow-up message (to anyone, about anything), using the "Send Message" button at the bottom of the member's information page, Groups.io does not leave any history behind in its logs. Nothing in Admin > Activity, nothing in the member's "Activity History" or their "Email Delivery History".