In the interests of completeness…
The first 2 letters of the code are the ISO 2-character country code and the third is (usually) the initial of the currency itself. so for example CH – for Confoederatio Helvetica, ie. Switzerland, and F for Franc gives CHF, the Swiss Franc.

It’s all there in ISO 4217, if you really need more information…

AFA – Afghanistan Afghani
ALL – Albanian Lek
DZD – Algerian Dinar
ARS – Argentine Peso
AWG – Aruba Florin
AUD – Australian Dollar
BSD – Bahamian Dollar
BHD – Bahraini Dinar
BDT – Bangladesh Taka
BBD – Barbados Dollar
BZD – Belize Dollar
BMD – Bermuda Dollar
BTN – Bhutan Ngultrum
BOB – Bolivian Boliviano
BWP – Botswana Pula
BRL – Brazilian Real
GBP – British Pound
BND – Brunei Dollar
BIF – Burundi Franc
KHR – Cambodia Riel
CAD – Canadian Dollar
CVE – Cape Verde Escudo
KYD – Cayman Islands Dollar
CLP – Chilean Peso
CNY – Chinese Yuan
COP – Colombian Peso
KMF – Comoros Franc
CRC – Costa Rica Colon
HRK – Croatian Kuna
CUP – Cuban Peso
CYP – Cyprus Pound
CZK – Czech Koruna
DKK – Danish Krone
DJF – Dijibouti Franc
DOP – Dominican Peso
XCD – East Caribbean Dollar
EGP – Egyptian Pound
SVC – El Salvador Colon
EEK – Estonian Kroon
ETB – Ethiopian Birr
EUR – Euro
FKP – Falkland Islands Pound
GMD – Gambian Dalasi
GHC – Ghanian Cedi
GIP – Gibraltar Pound
GTQ – Guatemala Quetzal
GNF – Guinea Franc
GYD – Guyana Dollar
HTG – Haiti Gourde
HNL – Honduras Lempira
HKD – Hong Kong Dollar
HUF – Hungarian Forint
ISK – Iceland Krona
INR – Indian Rupee
IDR – Indonesian Rupiah
IQD – Iraqi Dinar
ILS – Israeli Shekel
JMD – Jamaican Dollar
JPY – Japanese Yen
JOD – Jordanian Dinar
KZT – Kazakhstan Tenge
KES – Kenyan Shilling
KRW – Korean Won
KWD – Kuwaiti Dinar
LAK – Lao Kip
LVL – Latvian Lat
LBP – Lebanese Pound
LSL – Lesotho Loti
LRD – Liberian Dollar
LYD – Libyan Dinar
LTL – Lithuanian Lita
MOP – Macau Pataca
MKD – Macedonian Denar
MGF – Malagasy Franc
MWK – Malawi Kwacha
MYR – Malaysian Ringgit
MVR – Maldives Rufiyaa
MTL – Maltese Lira
MRO – Mauritania Ougulya
MUR – Mauritius Rupee
MXN – Mexican Peso
MDL – Moldovan Leu
MNT – Mongolian Tugrik
MAD – Moroccan Dirham
MZM – Mozambique Metical
MMK – Myanmar Kyat
NAD – Namibian Dollar
NPR – Nepalese Rupee
ANG – Neth Antilles Guilder
NZD – New Zealand Dollar
NIO – Nicaragua Cordoba
NGN – Nigerian Naira
NOK – Norwegian Krone
OMR – Omani Rial
XPF – Pacific Franc
PKR – Pakistani Rupee
XPD – Palladium Ounces
PAB – Panama Balboa
PGK – Papua New Guinea Kina
PYG – Paraguayan Guarani
PEN – Peruvian Nuevo Sol
PHP – Philippine Peso
XPT – Platinum Ounces
PLN – Polish Zloty
QAR – Qatar Rial
ROL – Romanian Leu
RUB – Russian Rouble
WST – Samoa Tala
STD – Sao Tome Dobra
SAR – Saudi Arabian Riyal
SCR – Seychelles Rupee
SLL – Sierra Leone Leone
XAG – Silver Ounces
SGD – Singapore Dollar
SKK – Slovak Koruna
SIT – Slovenian Tolar
SBD – Solomon Islands Dollar
SOS – Somali Shilling
ZAR – South African Rand
LKR – Sri Lanka Rupee
SHP – St Helena Pound
SDD – Sudanese Dinar
SRG – Surinam Guilder
SZL – Swaziland Lilageni
SEK – Swedish Krona
TRY – Turkey Lira
CHF – Swiss Franc
SYP – Syrian Pound
TWD – Taiwan Dollar
TZS – Tanzanian Shilling
THB – Thai Baht
TOP – Tonga Pa’anga
TTD – Trinidad & Tobago Dollar
TND – Tunisian Dinar
TRL – Turkish Lira
USD – U.S. Dollar
AED – UAE Dirham
UGX – Ugandan Shilling
UAH – Ukraine Hryvnia
UYU – Uruguayan New Peso
VUV – Vanuatu Vatu
VEB – Venezuelan Bolivar
VND – Vietnam Dong
YER – Yemen Riyal
YUM – Yugoslav Dinar
ZMK – Zambian Kwacha
ZWD – Zimbabwe Dollar