Note that this reference documentation is identical to the help that is displayed in MATLAB when you type “help ft_senslabel”.

  FT_SENSLABEL returns a list of predefined sensor labels given the
  EEG or MEG system type which can be used to detect the type of data.
  Use as
   label = ft_senslabel(type)
  The input sensor array type can be any of the following
  It is also possible to specify
  although for these an empty set of labels (i.e. {}) will be returned.