An identifier for the collection or dataset from which the record was derived.

`http://biocol.org/urn:lsid:biocol.org:col:1001`, `http://grbio.org/cool/p5fp-c036`

For physical specimens, the recommended best practice is to use an identifier from a collections registry such as the Global Registry of Biodiversity Repositories (http://grbio.org/).

Collection ID