A FundRef1 identifier assigned to an Organisation unit.
FundRef identifiers are assigned to organizations that (also) fund research.
Besides those of Agent Identifier:
FundRef ID : FundFef ID Type
None besides those of Agent Identifier.
A FundRef Identifier can only be assigned to an Organisation that also fund research, not other subtypes of Agent.
[1] Crossref funder ID. Wikidata property. Available from https://www.wikidata.org/wiki/Property:P3153