A shortage of coins after the war seriously hinders the rebuilding of public phone service. One development is the currency-type public telephone, which is designed to accept paper bank notes. A coin-operated model is removed and fitted with a box that has a wide slot at the top to accept paper currency, and a large notice is attached explaining that either coins or paper money may be used. Users themselves report payment of charges, so that this public telephone is also based on trust in the public to respect the 'honor system.'