As a common language to represent annotations for models, we have developed, in close collaboration with the COMBINE community, the OMEX metadata specification. This standard provides not only the specification of sharable, RDF formatted annotations, but also detailed examples and a set of recommended biological ontologies to use in those annotations. This standard is a critical technical backbone that can enable improved semantic search, and allow research to better compare models and the variables and terms that they use. As described in our software products, this specification provides the core representation of annotations for tools such as pyomexmeta and SemGen.
Version 1.2 of the specification is described in Gennari et al, 2021, and the initial consensus among COMBINE researchers and modelers was described in Neal et al, 2019.