Version 1.4.2 is a convenience and bugfix release of Sherpa. The main new feature compared to 1.4.1 is the introduction of the TUNE parameter which can be set to NNPDF23, NNPDF23_UEup, NNPDF23_UEdown, CT10, CT10_UEup, and CT10_UEdown. The CT10 option is the default setting (no change to 1.4.1), NNPDF23 provides settings for NNPDF 2.3, and the UEup and UEdown variants change the underlying event activity by +/-10%.