Table 1.

History of NLM author-indexing policy

DatesPolicy
1966-1984MEDLINE did not limit the number of authors.
1984-1995NLM limited the number of authors to 10, with “et al.” as the eleventh occurrence.
1996-1999NLM increased the limit from 10 to 25. If there were more than 25 authors, the first 24 were listed, the last author was used as the 25th, and the twenty-sixth and beyond became “et al.”.
2000-presentMEDLINE does not limit the number of authors.

From: PubMed: The Bibliographic Database

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