I'm attempting to write a currency formatting function using Intl.NumberFormat.
It works correctly when I pass it things like USD, or EUR as the currency, but seems to break when I pass it more obscure currency codes like PLN or COL, and instead of displaying their symbols as requested it displays the Codes. It is clearly recognizing the code because when I ask it to display the name instead it works correctly:

```
Intl.NumberFormat("en-US",{
  style:'currency',
  minimumIntegerDigits:1,
  currency: 'PLN',
  currencyDisplay: 'symbol'
}).format(43);

```

Displays "PLN43" while

```
Intl.NumberFormat("en-US",{
  style:'currency',
  minimumIntegerDigits:1,
  currency: 'PLN',
  currencyDisplay: 'name'
}).format(43);

```

Displays "43.00 Polish zlotys"