Synthetic stretched period echelle diagram built from Eq. (54), showing modelled mixed-mode frequencies affected by rotation with Ω_core = 0.5 μHz and magnetic-field strengths increasing left to right with B₀ = 0.1 MG, B₀ = 0.2 MG, B₀ = 0.5 MG, and B₀ = 1 MG in the radiative interior. Purely rotationally split components are given for reference by background crosses on the first two panels. Coloured dots indicate the positions of the ℓ = 1 mixed modes of azimuthal order m ∈ {1, 0, −1}, respectively blue, red, and green dots. The horizontal black line delimits domains for which the rotational splitting is small compared to (see Gehan et al. 2018, for more details). Synthetic patterns above this line are typically representative of patterns of mixed modes for subgiants and early giants, and those below are associated with evolved red giants. The magnetic effect is small compared to rotational effects in white areas, is of the same order of magnitude as in orange areas, and is larger than δν_{rot, core, m} in red areas.