What’s a cf?
cf. is used mainly in legal writing. It means compare. Used when it’s a useful, relevant citation to a case but is not direct support for the proposition; situations where a case has relevance to the point but isn’t dispositive. Lawyers often use it in citations to cases that could be a problem for them but feel obliged to point the judge to the relevant case or he’ll come down on them. They use the cf. to point to the case and characterize it in favor of the point they are trying to make.