I know in Vietnam there was a the Route Pack system which went from 1-6 with 6A being Hanoi and 6B being Haiphong, I was told in Korea that there was a division of responsibility set up there as well, but I've never seen the layout described.
The following might have some information:
Dronescapes
,
fannum
,
michaelmaltby
,
M
MIflyer
,
MiTasol
,
S
Shortround6
,
Thumpalumpacus
,
X
XBe02Drvr
The following might have some information: