Cadit quaestio is a Latin expression that is used as a legal term and in some other contexts. The expression literally translates as "the question (quaestio) falls (cadit)". In legal contexts, cadit quaestio is used to indicate that an issue is no longer in question, often because a dispute (question) between two parties has either been settled, or dropped.
Video Cadit quaestio
'cq' copy editing mark
As a mark in copy editing, "cq" implies that the accuracy of a statement has been verified by the copy-editor. The origins of the mark are uncertain, but several sources have suggested that "cq" stands for "cadit quaestio", and indicates that the issue is no longer in question. In this context, "cq" should be distinguished from "sic", used in published pieces to indicate that a quote has been transcribed verbatim, without correcting perceived errors in the original source.
Maps Cadit quaestio
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Source of the article : Wikipedia