...Many scholarly publications today adhere to the so-called Ingelfinger rule, a term named after Franz J. Ingelfinger, a former editor of The New England Journal of Medicine, who implemented it in 1969. Put simply, it bars scientists from publishing the same paper in more than one journal, but many researchers view it as a more expansive ban on discussing their research prior to publication, especially with journalists. Those who break the rule risk exclusion from further publication within a journal, and it's considered by some as the industry trying to lock in profits.
Source: US News & World Report. Read full article. (link)