When getting reports for papers submitted to a peer-reviewed journal, referees sometimes suggest that some missing items be added to the list of references. In my short career I have seen all possible cases, from honest additions that were clearly necessary, through border-line literature where one could cite any one of a long list of possible sources, to blatant cases of citation shopping where the reviewers ask for 10 of their own papers to be added to the list.
Here, I am looking at the problem from the other side (the reviewer side). I recently refereed a paper for which I suggested that the authors look at a very recent paper, authored by researchers totally unrelated to me, that touches on a couple of issues that I thought were very relevant. Since that paper is so new, it is likely that they were not aware of its existence. Because of all the misbehavior I talked about in my first paragraph above, I am afraid that the authors of the paper I reviewed might assume I am one of the authors of the suggested paper.
I know I should never disclose my identity in a report, but what about stating who "I am not"? Something like this:
I think the authors should have a look at recent paper Nice New Paper, which might help with the interpretation of their results. This reviewer would like to add that he did not participate in said study.
In my opinion this would serve two purposes. 1) Clarify the legitimacy of my suggestion (I do not get anything from it) and 2) prevent the authors of the reviewed paper from suspecting it was the other guys who reviewed their paper and they are shopping for citations.
What are possible ethical considerations against this course of action from the points of view of editors and authors?