format - a(a) 0000 a

type:
private: symbol - white, background - black
truck, bus, taxi: symbol - black, background - yellow
government: symbol - white, background - red
transit: symbol - red, background - white

region - first(one or two) letter:
Java - first one letter or two letter, but first "A"(centre Java):

B - Jakarta
L - Surabaya
AB - Jogyakarta

Sumatra - two letter, first "B":

BA - Padang
BD - Bengkulu
BE - Lampung
BG - Palembang
BK - Medan
BM - Pekanbaru

Kalimantan - two letter, first "K"

DK - Bali


Indonesia
Embassies and Consulates
Road distance
Photo from Indonesia