In computational catalysis it is more common to create a selfconsistent local thermochemical network. A local thermochemical network may be anchored to any valid set of anchor species. These anchor species can be part of the reaction mechanism or additional species not present in the mechanism, and they can even be abstracted into elemental chemical potentials. In the context of ab initio thermodynamics, we can think of these reference species as being in a reservoir that is in equilibrium with our target species (adsorbate, gas-phase, or surface) . The reactions to form the target from the reference species can take or donate these references to the reservoir as an isothermal and isobaric process . This work details the numerous approaches to construct these local networks and the approaches that integrate the formation enthalpies of adsorbates into the global thermochemical network by anchoring the species to the standard reference set according to the IUPAC definition.