R-7 - Regulatory Road Sign of Greece. This sign was established in 1974 and replaced the "Parking ban" sign. Their main difference is in the shape of the white rectangle.
<a href="//commons.wikimedia.org/wiki/User:Peeperman" title="User:Peeperman">Peeperman</a>
<span class="int-own-work" lang="en">Own work</span>