Get the nick name of a license, which is a short (untranslated) string such as e.g. "CC BY-NC-ND 2.0 UK".
| license_ref |
a license reference string in form of a URI, e.g. "http://creativecommons.org/licenses/by-nc-nd/2.0/" |
|
the nick name of the license, or NULL if the license is unknown |