It's just directories containing text files. Mix and match to your preferences.
You can create a copy of
en_ES and edit
LC_CURRENCY by either copying from another locale definition or editing all settings yourself. The settings are documented here, in section 7.3.3 LC_MONETARY. One entry per line.
Using German (Euro currency) as example,
# indicates start of my explanation which is not part of the file:
EUR # International currency symbol and divider
Eu # Currency symbol (local) (I have honestly never seen this used in my life)
, # decimal point
. # digit group (e.g. thousands) separator
3;3 # grouping
# positive sign (here: none)
- # negatice sign
2 # number of fractional digits (internationally)
2 # number of fractional digits (local)
1 # currency symbol before non-negative value
1 # currency symbol and sign string are separated by a space from the non-negative value
1 # currency symbol before negative value
1 # currency symbol and sign string are separated by a space from the negative value
1 # sign precedes both quantity and symbol for non-negative numbers
1 # sign precedes both quantity and symbol for negative numbers
The file does not contain the digit configuration twice as indicated on that web page.