At least in Germany in restaurants glasses have to have a &quot;Füllstrich&quot; for this reason:<p>&gt; <a href="https:&#x2F;&#x2F;de.wikipedia.org&#x2F;wiki&#x2F;F%C3%BCllstrich" rel="nofollow">https:&#x2F;&#x2F;de.wikipedia.org&#x2F;wiki&#x2F;F%C3%BCllstrich</a><p>The &quot;Füllstrich&quot; is a small line at the glass with a number next to it with which you can easily check whether you got the claimed amount.