Envelope rotation Ω_env and derived parameters against observed frequencies and estimated core hydrogen fractions for 25 stars. The top panel shows the envelope rotation rate against the zonal mode frequency of the multiplet (f₀) and the second panel against the projected surface rotation rate f_rotsin i for the stars having this quantity available. The third and fourth panels display derived rotational properties against the evolutionary stage. In the former, we show an upper limit for the level of differential rotation (Ω_env/Ω_surf) and in the bottom panel the spin parameter (s) of the mode in the envelope. The colour-coding corresponds to the mode degree: l = 1 in blue and l = 2 in orange.