This should be standard SOP for all ontologies:

• mark creators and contributors in the header
• this should be the same as author lists for publications or talks about the ontology, or used to drive acknowledgment slides
• contribution via PR automatically confers contribution status
• meaningful contribution via github issue discussion may also confer contribution
• active participation in workshops may confer contribution

In general ontology maintainers should do due diligence to ensure inclusion but the system also relies on contributors self-nominating