&gt; Microsoft implemented it back in their glory days (irony intended) by changing the file formats in new versions of the Office suite so that documents created by newer versions of Office could not be read by older versions, thus forcing everyone to upgrade to the newer version in order to share data.<p>In fact, Microsoft released updates for older versions of Office (back to Word 2000, apparently!) which allowed them to read the new formats [1].<p>[1] <a href="https:&#x2F;&#x2F;support.office.com&#x2F;en-us&#x2F;article&#x2F;Open-a-Word-2007-document-in-an-earlier-version-of-Word-8FE47805-64A9-4CC5-A115-B148625FE043" rel="nofollow">https:&#x2F;&#x2F;support.office.com&#x2F;en-us&#x2F;article&#x2F;Open-a-Word-2007-do...</a>