Lawrence et al 2009 (doi:10.1098/rsta.2008.0237) introduced a metadata taxonomy which classified relevant metadata into Archive, Browse, Character, Discovery and Extra.
Working with CMS colleagues, we are addressing A metadata for managing data at scale, both in the context of the CF Conventions) and in our ExCALIData work.
We address B metadata both through our work on documenting climate models (ES-DOC) and managing heterogeneous data (such as MOLES - Parton et al, 2015, doi:10.2218/ijdc.v10i1.365).
ES-DOC is a form of provenance metadata. A key idea is that of defining numerical experiments, as we did for CMIP6. Currently our main contribution is through developing the ES-DOC schema itself and a self-contained library for working with the schema and instances of metadata conforming to it - the Python Ontology Specification Language, PYSOSL.