 The study compares and derives analytical conditions for multiple non-Markovianity indicators to detect the dynamics of a qubit subjected to general phase covariant noise, without the need to explicitly derive and specify the analytic form of the time-dependent coefficients. Additionally, measuring the non-Markovianity indicators gives us directly non-trivial information on the relations between the unknown decay rates if we assume only the general form of the master equation. This article was offered by J. Titanen, H. Lyra, B. Sokolov, and others.