A blue warning construction sign
<a href="//commons.wikimedia.org/wiki/User:Duesentrieb" title="User:Duesentrieb">Duesentrieb</a>, <a href="//commons.wikimedia.org/wiki/User:Penubag" title="User:Penubag">penubag</a>
self-made in Inkscape  <a href="//commons.wikimedia.org/wiki/File:Baustelle.svg" class="image"><img alt="Baustelle.svg" src="https://upload.wikimedia.org/wikipedia/commons/thumb/f/f4/Baustelle.svg/50px-Baustelle.svg.png" decoding="async" width="50" height="44" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/f/f4/Baustelle.svg/75px-Baustelle.svg.png 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/f/f4/Baustelle.svg/100px-Baustelle.svg.png 2x" data-file-width="700" data-file-height="613"></a> + <a href="//commons.wikimedia.org/wiki/File:Ambox_warning_blue.svg" class="image"><img alt="Ambox warning blue.svg" src="https://upload.wikimedia.org/wikipedia/commons/thumb/3/34/Ambox_warning_blue.svg/50px-Ambox_warning_blue.svg.png" decoding="async" width="50" height="43" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/3/34/Ambox_warning_blue.svg/75px-Ambox_warning_blue.svg.png 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/3/34/Ambox_warning_blue.svg/100px-Ambox_warning_blue.svg.png 2x" data-file-width="378" data-file-height="326"></a>