MONEY
The uptight ones who probably got straight A's and followed all the rules as children only consider USD, EUR,JPY, GBP, and CHF as major currencies. Then they label AUD, NZD, and CAD, as 'commodity currencies.
These three letters are known as is04217 currency codes. By 1973, the international organization for stadardization [iso] established the three letters codes for currencies that we use today. other nickname for USD are green backs, bones ,benjis, benjamins,  cheddar, paper ,loot, chese bread.