This is a social norm sometimes, but it is very much not sufficient for authorship according to the stated criteria at most journals and ethical standards board

This is a social norm sometimes, but it is very much not sufficient for authorship according to the stated criteria at most journals and ethical standards boards. Usually "authorship" is supposed to mean something like "a substantial contribution to the research content and full approval of the published text". For example, at Medical Physics, an author must: - Have made substantial contributions to conception and design, or acquisition of data, or analysis and interpretation of data; AND. - Been involved in drafting the manuscript or revising it critically for important intellectual content; AND. - Given final approval of the version to be published.