Comparison of Gaia-ESO (dashed black line) CCFs and NAC RE (other solid coloured lines) CCFs for a given HR10 (left; MJD = 56857.311765) and the corresponding HR21 (right; MJD = 56856.376009) observation of CNAME 23354061-4305405. The mask names are provided in the legend boxes. For each observation, all NACRE CCFs agree very well: they have the same shape, they exhibit the same number of stellar components at nearly identical radial velocities. While the HR21 Gaia-ESO CCF exhibits only one stellar component, our CCFs reveal the presence of two stars, in agreement with the HR10 observation. The CCFs are all normalised by their respective maximum for the sake of readability.