I've just been downvoted for "plagiarism", in that I subsequently edited my own answer to include a reference that was already present in someone else's.
It so happens that in this particular case I was already aware of the reference when I first made my post, but I'm not sure that's relevant. In fact I didn't use it originally because while constructing my answer, and searching for earlier usages, I'd discovered an older one I wasn't familiar with. I just wanted to post my half-complete answer while I looked into a possible connection.
Is there a general consensus on EL&U etiquette for this situation? Even as I ask this, I'm aware it might be thought inappropriate to post an answer that might well be revised/expanded shortly afterwards, quite apart from the possibility of replicating another's references.
I've no wish to defend any particular stance in this area too strongly, but I will just say that unless an answer seems to consist almost entirely of the same content as one single other, I'm inclined to think there's nothing wrong. Even to the extent that a single new answer formed entirely by combining two or more existing ones may actually be desirable.
To my mind the primary aim is to end up with a single answer that's unequivocably "correct" and better than all others. If that can be achieved by combining two "half-right" answers, and the existing posters haven't arranged among themselves to do this, I don't really see much of a problem.
Am I out of touch with the zeitgeist here?