In early 2014, COPE, together with Directory of Open Access Journals (DOAJ), Open Access Scholarly Publishers Association (OASPA), and World Association of Medical Editors (WAME), published a minimum set of criteria for journals and publishers to be assessed against when they apply for membership at one of our organisations. The Principles of Transparency and Best Practice in Scholarly Publishing were well received and have been instrumental in helping us to manage the increase in number, and quality, of membership applications we received.
The principles have now been revised and updated and the full criteria can be seen here (http://publicationethics.org/resources/guidelines-new/principles-transparency-and-best-practice-scholarly-publishing). We encourage authors and anyone else who is unfamiliar with a journal or publisher to use these criteria in assessing a journal. Feedback is welcome.