The term "predatory journal" was coined by Jeffrey Beall in 2012, but there is no agreed-upon definition of a "predatory journal". That said, the resources listed on this page provide checklists and strategies for evaluating unfamiliar journals, publishers, and conferences on a case-by-case basis. Many new "scam" as well as legitimate journals and conferences are launched each year, making the maintenance of comprehensive lists of predatory vs. legitimate publication outlets an impossible task.
Think. Check. Submit. is a cross-industry initiative to help researchers identify trusted journals in which to publish. The site provides a checklist (under "Check") to evaluate the trustworthiness of journals.
"The aim of Think. Check. Submit. is not to refer researchers to a particular set of journals, which will fall out of date quickly. Instead, we are focused on helping researchers make the most informed decisions possible about where to publish their work."
Think. Check. Attend. provides a checklist to help researchers evaluate conferences at which they may wish to present their research.