Delete a Label
You can delete a label using the DELETE method on the labels endpoint. You need a token with write privileges, otherwise a 401 or 403 will be sent back.
Selecting a label to delete is done with the same parameters as the GET endpoint.
In order to avoid massive deletions by mistake, you can only delete one label at a time.
DELETE http://host.28.io/v1/_queries/public/api/labels?token=c3049752-4d35-43da-82a2-f89f1b06f7a4&aid=foobar§ion=http://www.example.com/&name=foo:Concept&labelRole=http://www.xbrl.org/2003/role/verboseLabel&language=en-US
Further reference
The reference for the REST API is documented here.