Hrqls: I some restaurants is not possible to lock toilet doors:/ That is failing of restaurant, not a our national practice;))))

Yes there are 50Kč coins. They is also paper variant;) Most people dont like the coins, its quite heavy. ( ČR planing to change currenty to euro in few years, so the old paper 50Kč are not reprinted and coins are more and more often now)...
P.S.: Sory for my english