and to this day the Japanese government has refused to exchange these currencies. Some locals managed to escape poverty because they had hidden Straits dollars and Malayan dollars, the currencies in use before the Japanese invaded. Those with hidden stashes of the old dollars were able to use them the moment the British resumed control of Singapore and surrounding colonies, when they became valid again. A number of surviving occupation banknotes were stamped as war souvenirs, while their use as printing paper for rudimentary calendars for 1946 was also recorded. When these notes became obsolete, punch holes were made in the notes to indicate they had been "cancelled" and stripped of redeemable value. The present value of the currency as a collector's item remains mixed depending on their condition, the presence of serial numbers, the use of woven paper, and their use as specimens. Common notes lacking serial numbers are still worth below their printed value, while rarer versions are worth slightly over or several times their printed value. Notes stamped as war souvenirs are currently rare, while notes with 1946 calendar overprints fetch about RM3,000 (as of September 2006). Ten dollar-sized leaflets reprinting the ten dollar note's obverse were also air-dropped by British air forces during the Japanese occupation as a warning to the population of the potential worthlessness of the currency in the event of Japanese defeat. Fear among the population of possessing the leaflet led to their rarity and present high value (at an estimated RM3,000 as of September 2006). Banknotes The currency – both dollars and cents – was released solely in the form of banknotes, as metals were considered essential to the war effort. The notes retain certain features that were common among preceding currencies, such as the use of the dollar and cent currency name, albeit without the use of their respective currency symbols ($ and ¢). However, the languages used on the notes were reduced to English, and Japanese at the lower edge of the notes. Each note bears different obverse and reverse designs but retains similar layouts. Intended for circulation in Malaya, Singapore, Brunei, Sarawak and North Borneo, the notes were marked with stamped block letters that begin with "M" for "Malaya". 1, 5 and 10 dollars (1942) The first series of notes were originally of lower denominations of 1, 5 and 10 dollars, issued in 1942. Identical to the designs of