As a Czech, you already know that but the brief democratic Czecho—Slovak Federation (1989-1992) also had a "Hyphen war" (actually just an argument) where Slovakia was not content with the longest dash available and wanted an "and" in the middle, breaking grammatical rules. Greater disagreements later resulted in the countries' peaceful dissolution on New Year's Eve 1992.

But the languages are different enough to be distinct despite being largely mutually understandable (you can use Slovak in Czech courts to this day). This means there is no embarrassing doubling or tripling of legally required text like with Slovenian & Not Slovenian & Legally Distinct Not Slovenian.