The anti-contact rule, also known as rule 4.2 of professional conduct, is a rule prohibiting lawyers from discussing subject matter of any case they’re working on with someone the lawyer knows to be represented by another lawyer in the matter...
professional responsibility
(Wex page)
The work-product privilege (or “work-product doctrine”) protects from discovery by the opposing party "documents and tangible things that are prepared in anticipation of litigation or for trial." Federal Rule of Civil Procedure 26(b)(3)(A)....