Cadit quaestio is a Latin expression that is used as a legal term and in some other contexts.
The precise origin of the term is uncertain, but cq was identified as the shorthand form of correct in the 1879 Phillips Code, a set of abbreviations used in the transmission of press reports via telegraph, first published in 1879.
[4] Alternative explanations of the origin include an abbreviation for cadit quaestio, indicating that the issue is "no longer in question",[5][6] and an abbreviation for correct as quoted, which serves as a useful mnemonic.
[7] Cq is a mark for internal use only, intended for removal prior to publishing.
It should be distinguished from the unrelated mark sic, used in published pieces to indicate that a quote has been transcribed verbatim, without correction of perceived errors in the original source.