The Hyphen War was not just a thing of the 90’s, we were fighting over it during the whole Czecho-Slovak era , except the communist regime.
The following sheet is called Pittsburgh Agreement.
More info here: https://en.wikipedia.org/wiki/Pittsburgh_Agreement
As you can see, there’s no “Czechoslovakia”. Everything is hyphenated.
Even some postage stamps had “Česko-Slovensko” on them: