Subset examples of normalised CCF profiles, their Gaussian fit, and residual CCF profiles computed by subtracting the median CCF or their respective Gaussian fit to each one of them. The colour coding traces the pulsation phase. Shape modulations are computed with the curves ‘at rest’, centred around the mean RV. For readability, the curves are shown in their original non-centred frame. X Sgr and δ Cep are fundamental mode pulsators whereas BG Cru and Polaris are first overtone ones. Line-splitting is noticeable in BG Cru’s and X Sgr’s C(v) data sets.