Measurements of the flavour oscillations and time dependent $CP$ asymmetries of neutral $B$ mesons require the knowledge of the flavour of the reconstructed $B$ mesons at the time of their production. The methods to infer this information is called Flavour Tagging (FT).
The FT group is the Physics Performance Working Group responsible for:
development, implementation, and tuning of flavour tagging algorithms;
calibrations of the mistag rates of the algorithms in control samples of flavour specific decays;
determination of flavour tagging performance;
give strategies for dealing with systematic related to flavour tagging.