Franc
The Swiss franc (ISO code: CHF or 756), which appreciated significantly against the new European currency from April to September 2000, remains one of the world's strongest currencies, worth today around five-sixths of a euro. The Swiss franc is used in Switzerland and in Liechtenstein. Liechtenstein retains the ability to mint its own currency, the Liechtenstein franc, which it does from time to time for commemorative or emergency purposes.
Liechtenstein–Switzerland relations
At the request of Liechtenstein's government in 1919, Switzerland safeguards Liechtenstein's interests and citizens abroad. The two form a common economic and monetary area (Liechtenstein has used the Swiss franc (since 1920) and has had a customs union (since 1924) with Switzerland with open borders (though both are now also party to the Schengen Agreement). The countries also have a common patent system. Switzerland is empowered to enter into treaties on Liechtenstein's behalf if Liechtenstein is not represented at the treaty negotiations; this power has most often been exercised with treaties involving customs duties or procedures.