Amateur radio, commonly called "ham radio", is a hobby enjoyed by many people throughout the world (as of 2004 about 3 million worldwide, 70,000 in Germany, 5,000 in Norway, 57,000 in Canada, and 700,000 in the USA). A holder of an Amateur Radio licence has studied and passed required tests in his or her country and been issued a call sign by its government. This call sign is unique to the operator and is often a source of pride. The holder of a call sign uses it on the air to legally identify all voice and data communications. Amateur Radio should not be confused with CB radio, General Mobile Radio Service or Family Radio Service which are limited to voice operation, allowed lower power limits, fewer frequency allocations, and are unlicensed in most countries.