  The identification of charm jets is achieved at LHCb for data collected in
2015-2018 using a method based on the properties of displaced vertices
reconstructed and matched with jets. The performance of this method is
determined using a dijet calibration dataset recorded by the LHCb detector and
selected such that the jets are unbiased in quantities used in the tagging
algorithm. The charm-tagging efficiency is reported as a function of the
transverse momentum of the jet. The measured efficiencies are compared to those
obtained from simulation and found to be in good agreement.
