Question: Removed from circulation in 1999, the fillér was the Hungartian subunit of what Austro-Hungarian currency?

Context articles: Cash rounding
Dutch guilder
Italian lira
Fillér
Hungarian forint
Circulation (currency)
Portuguese Indian rupia
The Great Debasement
Austro-Hungarian gulden
Austro-Hungarian krone

Cash rounding or Swedish rounding (New Zealand English) occurs when the minimum unit of account is smaller than the lowest physical denomination of currency.
 The amount payable for a cash transaction is rounded to the nearest multiple of the minimum currency unit available, whereas transactions paid in other ways are not rounded (for example electronic funds transfer like credit cards, or negotiable instruments like cheques).
 Cash rounding typically occurs when low-denomination coins are removed from circulation owing to inflation.
 Cash rounding may be a compulsory legal requirement if such coins are no longer legal tender, or a voluntary practice where they remain in circulation but are scarce or impractical.
The Dutch guilder (Dutch: "gulden" , ] ) or fl.
 was the currency of the Netherlands from the 17th century until 2002, when it was replaced by the euro.
 Between 1999 and 2002, the guilder was officially a "national subunit" of the euro.
 However, physical payments could only be made in guilder, as no euro coins or banknotes were available.
 The Netherlands Antillean guilder is still in use in Curaçao and Sint Maarten (two countries in the Kingdom of the Netherlands), but this currency is distinct from the Dutch guilder.
 In 2004, the Surinamese guilder was replaced by the Surinamese dollar.
The lira (] ; plural "lire" ] ) was the currency of Italy between 1861 and 2002 and of the Albanian Kingdom between 1941 and 1943.
 Between 1999 and 2002, the Italian lira was officially a national subunit of the euro.
 However, cash payments could be made in lira only, as euro coins or notes were not yet available.
 The lira was also the currency of the Napoleonic Kingdom of Italy between 1807 and 1814.
The fillér ] was the name of various small change coins throughout Hungarian history.
 It was the ⁄ subdivision of the Austro-Hungarian and the Hungarian korona, the pengő and the forint.
 The name derives from the German word "Vierer" that means "number four" in English.
 Originally it was the name of the four-kreuzer coin.
 Due to significant inflation that took place after the fall of communism, fillér coins are no longer in circulation.
 The last fillér coin, worth 50 fillér (0.5 forint) was removed from circulation in 1999.
 However, it continues to be used in calculations, for example in the price of petrol (e.g. 310.9 forint), or in the prices of telephone calls.
The forint (sign: Ft; code: HUF) is the currency of Hungary.
 It was formerly divided into 100 fillér, but fillér coins are no longer in circulation.
 The introduction of the forint on 1 August 1946 was a crucial step in the post-World War II stabilization of the Hungarian economy, and the currency remained relatively stable until the 1980s.
 Transition to a market economy in the early 1990s adversely affected the value of the forint; inflation peaked at 35% in 1991.
 Since 2001, inflation is in single digits, and the forint has been declared fully convertible.
 As a member of the European Union, the long -term aim of the Hungarian government may be to replace the forint with the euro, but that does not appear to be likely until some time during the 2020s.
In monetary economics, circulation is the continuing use of individual units of a currency for transactions.
 Thus currency in circulation is the total value of currency (coins and paper currency) that has ever been issued minus the amount that has been removed from the economy by the central bank.
 More broadly, money in circulation is the total money supply of a country, which can be defined in various ways always including currency and also including some types of bank deposits.
The rupia was the currency of Portuguese India sometime after 1668 until 1958.
 Prior to 1668, the currency unit was "Xerafim" ("xerafin", "xeraphin").
 In 1666, the Portuguese administration struck a silver coin calling it double "xerafin" and this was declared equal to a rupia in circulation in India outside of Portuguese possesions.
 A "xerafim" was a convertible subunit of "rupia", and it was unique to Portuguese colonies in India.
 One rupia equalled two xerafims.
The Great Debasement (1544-1551) was a currency debasement policy introduced by in 1544 England under the order of Henry VIII which saw the amount of precious metal in gold and silver coins reduced and in some cases replaced entirely with cheaper base metals such as copper.
 Overspending by Henry VIII to pay for his lavish lifestyle and to fund foreign wars with France and Scotland are cited as reasons for the policy's introduction.
 The main aim of the policy was to increase revenue for the Crown at the cost of taxpayers through savings in currency production with less bullion being required to mint new coins.
 During debasement gold standards dropped from the previous standard of 23 carat to as low as 20 carat while silver was reduced from 92.5% sterling silver to just 25%.
 Revoked in 1551 by Edward VI the policy's economic effects continued for many years until 1560 when all debased currency was removed from circulation.
The Gulden or forint (German: "Gulden" , Hungarian: "forint" , Croatian: "forinta/florin" , Czech: "zlatý" ) was the currency of the lands of the House of Habsburg between 1754 and 1892 (known as the Austrian Empire from 1804 to 1867 and the Austro-Hungarian Monarchy after 1867), when it was replaced by the Krone/korona as part of the introduction of the gold standard.
 In Austria, the Gulden was initially divided into 60 Kreuzer, and in Hungary, the forint was divided into 60 krajczár.
 The currency was decimalized in 1857, using the same names for the unit and subunit.
The Krone or korona (German: "Krone" , Hungarian: "korona" , , Czech and Slovak: "koruna" ) was the official currency of the Austro-Hungarian Empire from 1892 (when it replaced the gulden, forint, florén or zlatka as part of the adoption of the gold standard) until the dissolution of the empire in 1918.
 The subunit was one hundredth of the main unit, and was called a "Heller " in the Austrian and a "fillér " (or "halier " in Slovak and "haléř" in Czech) in the Hungarian part of the Empire.