RTTOV v12.3 has been released. Updates from v12.2 include: the new CAMEL IR emissivity atlas derived from multi-year (2000-2016) climatology, new options for treatment of Lambertian surfaces, an update to the MFASIS fast visible cloud parameterisation to account for variable water vapour in affected channels, an updated parameterisation of the Baran ice optical property database with greater spectral consistency from the visible to the far-IR, a new tool to enable generation of custom aerosol optical property files for visible/IR scattering simulations, a new subroutine that provides a simple way to pass scaled copies of the reference trace gas profiles into RTTOV, and numerous updates to extend the capabilities of the HTFRTC model within RTTOV. See the RTTOV pages for more information.