http://www.sciencemag.org/news/2021/06/when-self-plagiarism-ok-new-guidelines-offer-researchers-rules-recycling-text

Although researchers often have valid reasons to take text they have already published and reuse it in new papers, peers often frown on such recycling as “self-plagiarism.” But when Cary Moskovitz of Duke University, who studies the teaching of writing, went looking for guidance on self-plagiarism for his students, he came up empty-handed.

“There was almost no actual research into the practice,” he says. Scholars hadn’t really examined how frequently researchers recycle their text, whether that reuse constitutes copyright infringement, or what kinds of reuse researchers believe is right or wrong. So, Moskovitz set out to fill the gap. Today, his Text Recycling Research Project (TRRP) released guidance for editors and authors, describing when the practice is both ethical and legal, and how to present reused text transparently.