Here’s case in point, a retraction notice from the Botswana Journal of Agriculture & Applied Sciences:
Below is the letter written to the author(s) of the article “Mabe, R. Capacity development and the need for extension services: A case of mentorship for emerging sugarcane farmers’ in South Africa” by the Chief Editor of BOJAAS with regard to redundant publication.
Professor O. R. Madibela (2014)
This memo is about the paper that you submitted to Botswana Journal of Agriculture and Applied Sciences titled “Capacity development and the need for extension services: A case of mentorship for emerging sugarcane farmers’ in South Africa”
This paper is with printers and we were doing the last proof reading when we noticed that one of the references, Enshayan, K., Stinner, D. and Stinner, B. (1992). Farmer to Farmer. Journal of Soil and Water Conservation, 47:127–130 was missing a volume number. We could have called you to supply us with this information but we thought it will waste time so we search the internet for the information. We were surprised that the same work you have submitted to us has already being published somewhere else (see attached article). It would be unethical for you and for me as the Chief Editor to go ahead and publish this research. It is clearly stated in the Guidelines for Authors that “It is understood that submitting an article to BOJAAS means that it is not concurrently being considered by another journal elsewhere” As such, your paper has been withdrawn from publishing.
Hat tip: Rolf Degen