The <a href="https://en.wikipedia.org/wiki/International_System_of_Units" id="mwAbQ" rel="mw:WikiLink" title="International System of Units">International System of Units</a> (SI): The base units are redefined, making the <a href="https://en.wikipedia.org/wiki/International_Prototype_of_the_Kilogram" id="mwAbU" rel="mw:WikiLink" title="International Prototype of the Kilogram">international prototype of the kilogram</a> obsolete.