sentences:  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.