Human computational phantoms for radiation dosimetry simulations with the software suite MCNP (Monte-Carlo N-particle Transport Code) have been implemented at FOI since a few years back. These phantoms, denoted FOI-CAP (FOI-Computational Anthropomorphic Phantoms), are so called stylized phantoms, which means the anatomy of the human is approximated by polynomials in the 3D spatial domain. Nevertheless, they are able to produce reliable dosimetric results for many of the applications of interest at FOI. Therefore, they are also called the FOI stylized reference dosimetry phantoms. In this work male and female FOI-CAP have been extended to also resemble versions of the phantoms in sitting posture. One particular area of use is in-vehicle dosimetry. Some minor reworks, based on results from stochastic volume determination via ray tracing, on other organs or body parts in the phantoms are presented as well. These include considerable modifications of the facial skeleton for which the volume and mass is now updated. The latest volume and mass data for all organs and body parts included in the phantoms (version 4.1) are given, along with the origin of these data. Calculated reference organ dose data is presented for both postures, three gamma energies and several reference geometries.