Seat belt that required a particular technical approach would rapidly become dated as motor manufacturers would tool up for a particular standard which could not easily be changed. For example, in 1969 there were competing designs for lap and three-point seat belts, rapidly tilting seats, and airbags being developed. But as countries started to mandate seat belt restraints the global auto industry invested in the tooling and standardized exclusively on seat belts, and ignored other restraint designs such as air bags for several decades As of 2016, seat belt laws can be divided into two categories: primary and secondary. A primary seat
Postage stamps and postal history of Czechoslovakia Postage stamps and postal history of Czechoslovakia This is a survey of the postage stamps and postal history of Czechoslovakia. Czechoslovakia was a country in Central Europe which existed from October 1918, when it declared its independence from the Austro-Hungarian Empire, until 1992. From 1939 to 1945 the state did not have de facto existence, due to its forced division and partial incorporation into Nazi Germany, but the Czechoslovak government-in-exile nevertheless continued to exist during this time period. On 1 January 1993 Czechoslovakia peacefully split into the Czech Republic and Slovakia. Before the establishment of the Czechoslovak Republic, stamps of