Kiel diagrams for models of NGC 6910-18. Leftmost panel: models that satisfy all criteria, (i) to (v), for the radial mode (f₁). Black and blue dots correspond to modes with rotational velocities of 250 and 97 km s⁻¹, respectively. The green area is the same as in Fig. 11; blue vertical lines correspond to the adopted T_eff limits for NGC 6910-18. The models define three areas (shown with red boundaries) corresponding to f₁ identified as fundamental (F), first overtone (1O), and second overtone (2O) radial mode. Remaining four panels: location of models satisfying all criteria for the f₅ mode assuming (from left to right) l = 0, 1, 2, and 3. The colours of the dots have the same meaning as in the leftmost panel.