Panels a–c: black crosses represent the randomly extracted K_s-band phase points over the light curve of the OGLE RRc variable 11254. Grey dashed lines display the template fits to the individual phase points. The Fourier (panel a), PEGASUS (panel b), and J96 (panel c) RRc light-curve templates are also displayed. The ID of the RRL is labelled. Panels d–f: same as panels a–c, but for the OGLE RRab variable 14578. The RRab1 light-curve templates are displayed. Panels g–i: same as panels a–c, but for the OGLE RRab variable 14806. The RRab2 light-curve templates are displayed. Panels j–l: same as panels a–c, but for the OGLE RRab variable 14958. The RRab3 light-curve templates are displayed.