  NLTE effects - the errors caused by assuming local thermodynamic equilibrium
(LTE) - on LiBeB abundance determinations for cool stars are discussed. These
NLTE effects are significant in many cases for B I and Li I lines. The Be II
313 nm lines are not formed under LTE circumstances, but the NLTE effects on
equivalent widths seem to be rather small. Reasons for doing LTE abundance
analysis are discussed and confronted with the reasons for doing NLTE abundance
analysis. The impact of three-dimensional photospheric inhomogeneity on line
formation is discussed - there are not many definite results on this yet, but
there may be soon.
