single value constraint
['access status', 'open access', 'single value constraint', 'copyright license', 'May be used also with P1436 (collection or exhibition size) to indicate the access status of a collection or archive. May also be used directly as main value to indicate the access status of, e.g., the proceedings of an academic conference (Q2020153) or conference series (Q15900647) or news media (Q1193236) or broadcaster (Q15265344)']