Hidden Recruitment Resources

Is there any map or guide on the hidden resources for unit recruitment?

I found this map in the map thread that's stickied, but it doesn't give any information on the n y resources.

Spoiler Alert, click show to read: 

example from the EDB:

recruit "hellenistic infantry hoplitai" 0 requires factions { thrace, macedon, } and hidden_resource NW and hidden_resource A and hidden_resource n1 and hidden_resource n2 and hidden_resource y4 and hidden_resource y8

Any help on solving this n and y puzzle would be much appreciated. I did numerous searches on the forum, but they all came back with nothing.

Spoiler Alert, click show to read: 

The resources placed in each province are speciifed in EB\Data\world\maps\base\descr_regions.txt.

WOOH, I love you Atilius, you handsome man!