Ethics committee approval is required for studies in which data are collected from participants through surveys, interviews (including field elicitation), observation or experiments. The name of the committee and the date and number of its decision are stated in the methods part and on the first or last page of the paper. Retrospective approval is not required for data collected before 2020; the date of collection is stated in the paper. Papers based on the author's own judgements, on published sources or on openly accessible corpora require no approval, and this is stated in one sentence.
