Let \(M\) be a non-zero, finite module over a noetherian ring \(A\). It is well known that if \(A\) is a local ring, then every permutation of an \(M\)-sequence is an \(M\)-sequence. In the paper under review the author studies modules \(M\) which satisfy the condition that the \(Aa\)-adic topology on \(M\) is separated for every \(M\)-regular element \(a\).