res inter alios acta, aliis nec nocet nec prodest → a thing done between some does not harm or benefit others
res inter alios acta → something transacted between other parties
Res inter alios acta, aliis nec nocet nec prodest (Latin for "a thing done between some does not harm or benefit others") is a law doctrine which holds that a contract cannot adversely affect the rights of one who is not a party to the contract.
"Res inter alios" has a common meaning: "A matter between others is not our business."
Res inter alios acta - Wikipedia