Mean magnetic field modulus of HD 965 against rotation phase. The different symbols identify the instrumental configuration from which the ⟨B⟩ value was obtained, as follows. Filled in circles (dark blue) correspond to CAT + CES LC; asterisk (turquoise) corresponds to CAT + CES LC, lower resolution; open circle (steel blue) corresponds to CAT + CES SC; open squares (brown) correspond to OHP 1.52 m + AURELIE; filled in triangles (violet) correspond to CFHT + Gecko (all previous symbols are identical to Mathys 2017); four-pointed open stars (light green) correspond to UT2 + UVES; and filled in pentagons (yellow) correspond to 3.6 m + HARPS. The short-dashed line (dark green) corresponds to the superposition of low-order multipoles as discussed in Sect. 4. The dotted lines (blue) correspond to ±1 standard deviation of the individual measurements about their average value (red dashed line).