Comments in Physical Review Letters
Physical Review Letters publishes timely Comments on its Letters. Authors of the Letter to which a Comment is directed may respond to the Comment, and the Comment will be published together with the Reply by the original authors if the Comment and Reply are valid and of interest. If the Comment meets our criteria it will be published whether a Reply is published or not. Just as Letters are restricted in length by journal policies, the lengths of Comments and Replies are restricted to 750 words each (roughly one journal page).
A Comment corrects or criticizes a specific Letter. The opening paragraph of the Comment should clearly indicate the Letter to which it is directed, and the point of the Comment. A Comment must be substantive; just as Letters are acceptable only if they are of considerable interest, only important Comments on Letters will be accepted. The Comment must be centrally related to the Letter and not simply a discussion of the general topic. The editors will not accept a Comment on a Letter by any of the authors of the Letter; the Comment format is not meant to be a vehicle for addenda. Neither are Comments intended as a means to establish priorities or to rectify bibliographic oversights. A corrective Comment will be deemed unnecessary if an Erratum would suffice. Critical Comments must be written in a collegial tone; polemical Comments will be rejected forthwith.
In general, each Comment is sent to an author of the subject Letter and one (or more) of the following responses is requested.
The author of the Letter is not asked to review the Comment as an anonymous referee. The editors will consult an independent, anonymous referee if they deem it useful in determining the suitability for publication of the Comment (and Reply, if any). In any transmission, the Reply or the reaction of the author is not treated anonymously.
Just as a Comment must be written in a collegial tone, must be free from polemics, must be pertinent, and must be free from egregious errors to be considered for publication, the Reply must also conform to these requirements. A Comment and Reply (if both are acceptable) must appear in the same issue. The editors will not excessively delay the publication of a suitable Comment because of the lack of an adequate Reply. Authors of a Comment are encouraged to send their Comment first to the authors of the Letter in question for a direct response, although the editors do not require such a step. Reply Comments are shown to the authors of the Comment prior to publication or when other need arises. Substantial revision of a Comment in response to the Reply will usually be interpreted by the editors as a sign that the Comment was misconceived, and might be cause for a rejection of the Comment.