All three are written agreements or written notes on reciprocal agreements between management and the union speaking together on behalf of the workers. As a general rule, however, the collective agreement is used to describe the framework agreement, the document that covers a wide range of working conditions and is valid for two or three years without amendment. Then it will be renegotiated. So-called memos usually cover individual and less important topics. You do not have an expiry date; that is, they remain in force until the parties agree otherwise. Legally, these three acronyms mean the same thing. .