Created using feedback from https://lemmy.cafe/post/4823550. Maybe this can be useful.
Transcript: See something off? Do your part to keep the Lemmy community safe:
R - Read the rules of the community.
E - Explain your report, including rule # when possible.
P - Provide context the mods should know.
O - Opt-out, disengage, downvote or block. Don't add to the drama.
R - Reach out or report right away. *For extremely time-sensitive content (CSAM, gore) DM an admin via Matrix: Instance homepage > Sidebar > click admin's @username > Send Secure Message
T - Trust your instincts. If in doubt, report it.
It’s probably not so much an oversight as a natural consequence of the open nature of Lemmy. Same reason DMs on here are not technically private. Even if you implemented an anonymous report feature, instance admins could probably identify the user easily.