Anita is very true.
Even official name of state was from the 28th October 1918 Czechoslovakian republic, in the first years 1919 and 1920 you can also find labels or marks written not together "Czechoslovakia" but Czecho-Slovakia or French exquivalent of this. In later years always together - exeption is period between November 1938 - March 1939.
Why I am speaking so widely about this little "dash".
This little "dash" was always big political issue in relationship between two nations in former Czechoslovakia - Czech and Slovak nation. For friends who are not famililiar with it, Czech and Slovak language is very simmilar, little children can understand each other without interpreting. In period of first Czechoslovak republic - 1918 - 1938 was officialy undertaken concept of unique "Czechoslovakian" nation. It should be remembered that Czech part of country was industrial, good educated and developed, Slovak part was rather agricultural. Politicians had believed that this "fabricated" Czechoslovakian nation would better resist Germans at Czech side and Huńgarians at Slovak side. Czech had accepted this concept of one nation, but some Slovaks had own national ambitions. Therefore at the first moment when it was possible, in 1939 after ocupation of Czech part of Czechoslovakia by nazis, Slovaks had declared own Slovak state.
After WWII was Czechoslovakia renewed again, only the most east part of country was taken by Russians and connected to Soviet Union. Soon won communists and the Slovak national ambitions were suppressed. Significantly in very hard times for Czechoslovakia - in 1968 just after the Russian invasion Slovak's ambitions had grown again and Czechoslovakia was constituted like "federal republic". But it was rather game, becouse all rule was still in communists hands.
The end of Czechoslovakia came soon after the velvet revolution in 1989. In 1990 started so called "dash war". Slovaks wanted to show that they are the nation also in the name of state and have asked for introducing "dash" to name of Czechoslovakia (Czecho-Slovakia). For Czechs this was unnaceptable, this name reminiscented the period of second republic after German annection, silly problem but quite emotional. Result was that the state had been renamed to Czech and Slovak Federal Republic - shortly written in Czech language "Československo" in Slovak language "Česko-Slovensko"
It did not help, Slovak separatistic ambitions were actively supported by about 20 percent Slovak voters, the futer existence of one Czechoslovak state was ineffective a irational. It was agreed in peace that country will be splitted from January 1st 1993, every Czechoslovakian citisen has got chance to select his nation and state without any restrictions according his personal wish. Two month later was divided also common currency. Nowadays both states are member of EU, Czechs keep their currency Czech Koruna, Slovaks joined Euro this January.