Wiley advises these general rules:
A journal should maintain a consistent policy on unsubmitting. The balance is between creating work for the editorial office and the risk of deterring authors. Consider these questions when creating or revising your policy on unsubmitting:
Common reasons for unsubmitting include:
*Wiley Editing Services offers an English Language Editing service, to which you can refer authors when unsubmitting for language reasons.
If you repeatedly find yourself unsubmitting for the same reason(s) then it may be an indication that the journal’s guidelines to authors are unclear. Review your guidelines regularly, to ensure they are up-to-date and clearly explain the journal's requirements. You may also consider adding customized questions for the author to answer at submission stage. For example "please check and confirm your references are formatted in APA style".
When a manuscript is returned, it should include an explanation of why the manuscript was sent back. This should make it clear if the author is expected to edit and resubmit (rather than the author thinking it has been rejected). It is useful to make reference to the guidelines to authors (with a link if possible), e.g. "as stated in our author guidelines, manuscripts should be no longer than 5000 words'". It is also useful to make sure that the instructions for resubmission are clear.
It may be helpful to create standard template letters for the common reasons to use when unsubmitting.