From what they write in their live demo[1], it&#x27;s about the dimensions of the plate rather than what&#x27;s on them:<p>&gt; OpenALPR supports both North American style (12 inches by 6 inches) and European style (52 cm by 11 cm) license plates.<p>That makes a bit more sense. Then again, the &quot;Country&quot; field there gives a choice of North American, European, Australia, Great Britain, Singapore, Korea.<p>I wonder if accuracy couldn&#x27;t be improved quite a bit if they included heuristics for individual countries. For instance, German licence plates should be really easy to read thanks to their &quot;forgery-impeding typeface&quot;[2] which has uniquely distinctive features for each letter.<p>It&#x27;s also not guaranteed that all European licence plates have those dimensions. Motorcycles and tractors for instance have taller, narrower plates, and cars where regular plates wouldn&#x27;t fit (like imported or antique cars) can get special plates as well.<p>And then of course there&#x27;s Switzerland which has wildly different dimensions and has changed its mind every few years[3].<p>[1] <a href="http:&#x2F;&#x2F;www.openalpr.com&#x2F;demo-image.html" rel="nofollow">http:&#x2F;&#x2F;www.openalpr.com&#x2F;demo-image.html</a><p>[2] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;FE-Schrift" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;FE-Schrift</a><p>[3] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Vehicle_registration_plates_of_Switzerland" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Vehicle_registration_plates_of...</a>