Is it legal to upload a paper to arXiv when it is under double blind review for one of the IEEE journals? Is it legal to upload a paper to arXiv when it is under double blind review for one of the IEEE journals? I am suspicious that it may violate the double blind review requirements and I couldn't find any thing in the journal's homepage specific to this issue. In general IEEE allows preprint versions to be uploaded to arXiv.
I have just received an email from the editor and I am writing it here

Dear Dr. * * *,

We cannot prevent an author to upload her/his paper to Arxiv. However, because of the double-blind process applied in Communication Letters, we don’t encourage it.
There is only one restriction: Your paper should stand alone without any supplementary material and/or reference to an ArXiv post.

Sincerely,