Vancouver system

The Vancouver system, also known as Vancouver reference style or the author–number system, is a citation style that uses numbers within the text that refer to numbered entries in the reference list. It is popular in the physical sciences and is one of two referencing systems normally used in medicine, the other being the author–date, or "Harvard", system. Vancouver style is used by MEDLINE and PubMed.

Hundreds of scientific journals use author-number systems. They all follow the same essential logic (that is, numbered citations pointing to numbered list entries), although the trivial details of the output mask, such as punctuation, casing of titles, and italic, vary widely among them. They have existed for over a century; the names "Vancouver system" or "Vancouver style" have existed since 1978. The latest version of the latter is Citing Medicine, per the References > Style and Format section of the ICMJE Recommendations.

In the broad sense, the Vancouver system refers to any author-number system regardless of the formatting details. A narrower definition of the Vancouver system refers to a specific author-number format specified by the ICMJE Recommendations (Uniform Requirements for Manuscripts, URM). For example, the AMA reference style is Vancouver style in the broad sense because it is an author-number system that conforms to the URM, but not in the narrow sense because its formatting differs in some minor details from the NLM/PubMed style (such as what is italicized and whether the citation numbers are bracketed).

Author–number systems have existed for over a century and throughout that time have been one of the main types of citation style in scientific journals (the other being author–date). In 1978, a committee of editors from various medical journals, the International Committee of Medical Journal Editors (ICMJE), met in Vancouver, BC, Canada to agree to a unified set of requirements for the articles of such journals. This meeting led to the establishment of the Uniform Requirements for Manuscripts Submitted to Biomedical Journals (URMs). Part of the URMs is the reference style, for which the ICMJE selected the long-established author–number principle.

...
Wikipedia