This Magento module adds all regions of Czech Republic to the optional customer address attribute region, which is used often for US based customers and corresponding US states. Compatible with Magento 1.x and most of M1 clones and forks like Open Mage.
NOTE: You need to have MySQL privileges for creating and calling procedures/functions for your database user used for Magento.
Support and further development of this module is available from Stanislav Puffler - Open Mage.