User Schifter created a test log for SCP-1600 without asking the original author (Anqxyr) for permission. It turns out this is not against the rules, and Anqxyr had expressed interest in a log in the comments. I sent the following message:
Dear Schifter,
It's been brought to staff attention that you created test logs for SCP-1600 without consulting the original author first. The author had expressed interest in test logs being made, and it's not actually against the rules to create supplements for the SCPs of others, but it would be appreciated if in the future you'd get creator permission before writing supplements for works that aren't your own. That said I encourage your participation- just, make sure the original authors are on board.
Thank you and best wishes,
Vezaz
EDIT: It turns out Schifter did ask for permission, to which Anqxyr replied "I would not be against it." So, lessons on communication for all. I have messaged Schifter saying he's fine.
http://www.scp-wiki.net/forum/t-466570/scp-1600#post-1861135
I sing of arms and the man
Storm-tossed by Hera's jealousy