Hi, since the phone meeting was cut, here are some remarks which I wanted to make [hoping that they are not too obvious to you ;-)] Daniele's list is quite exhaustive, but I find more clear to factorize the systematic uncertainties into 4 categories: 1) MC parameterization of B->D l nu decays, in terms of absolute/relative D, D*, D** BRs and distributions 2) MC parameterization of D decays (cascades and topological BRs) 3) MC signal composition (resonant vs. non-resonant relative normalization and distributions) 4) detector effects (PID, resolutions in Mx, etc.) All the quantities used in the analysis (BG_u, BG_sl, the efficiencies) are affected by effects from the above categories, each one in different proportions. For instance, Eff^u_sel is mostly affected by 3) whereas BG_u is affected by 1), 2) and 4). I find that thinking in terms of these categories allows also to take correlations into account and avoid double counting/overshooting in a more natural way. Morevoer, concerning 1) and 2), we already have some guidance and estimates, based on the V_cb analysis [BAD 218]. I have not mentioned the uncertainty from the M_es fits, but it is trivial, isn't it? :-) Ciao, Concezio.