Czech Republic (CZ) on the Raymond family tree
Czech Republic was a nation-state on the planet Earth. It contained the city of Prague, and Bohemia. The abbreviation for this nation was CZ. (TNG: "The Neutral Zone", okudagram)
A 20th century-era political map of Earth was stored in the USS Enterprise library computer in 2254. The location of this country was depicted on this map. This map was among the materials viewed by the Talosians when they scanned the Enterprise computer. (TOS-R: "The Cage")
The name of this state was not mentioned in dialog; the remastered Clare Raymond family tree mentioned "Prague, CZ" as birthplace for Eric Bruno Raymond late 21st century and "CZ" is the code for the "Czech Republic" in the ISO 3166 directory.