Currently the information printed consists of the estimated posterior for k and basic parameters
of the MCMC simulation: number of sweeps, length of burnin, random number seed to replicate the run, and confirmation of which MCMC moves used, and acceptance statistics for each type of trans-dimensional move.
References
Richardson and Green (J. R. Statist. Soc. B, 1997, 59, 731-792; see also the
correction in J. R. Statist. Soc. B, 1998, 60, 661)