Types of predatory publishers
Phisher
Phishers make empty promises to potential authors, such as a speedy peer review process and false information about a journal's impact factor. and then charge fees after the paper has been "accepted for publication." These fees are usually not disclosed prior to the author submitting an article and, after acceptance, phishers may then demand payment even though no contracts nor author/copyright agreements have been signed.
Imposters/Hijackers present themselves as an established journal or publication associated with a well-known brand or professional society. The journal titles of conference names are deceptive and scholars must be diligent when approached by such predators lest they publish or present with the fraudulent party. They make great efforts to look "real."
Trojan Horses may have a deceptively professional looking website with a long list of journals or conference associations. However, when a potential author takes a closer look, the sites are littered with numerous red flags. For instance, the journal volume and issue may be listed as the first volume or there may be none at all; published materials in the journals are poorly written or plagiarized articles from other reputable journals; or there may be evidence of a practice called white hat journal hoaxing.
Unicorns are publishers that may be legitimate, but they are poor in several areas. For example, they may not have an archiving policy which means an article can vanish with no warning; they could have a vague or non-existent peer review policy; or they could have questionable ethics regarding their methods of publishing.
*Credit and undying thanks for these categories goes to Megan N. O'Donnell, Data Services Librarian, at Iowa State University. The graphic icons used in this section are from icons8. Reuse of the icons requires a link back to icons8.