I'm really confused how supply is produced in TYW. Manual mentions supply chit (SC) production as follows:
Level 1 city = 1 basic SC (which equals to 5 supply points, 0 ammo points)
Level 2+ city = 1 full SC (which equals to 5 supply points, 2 ammo points) per level
Port = 1 full SC per port level
Fort = 1 full SC per fort level
Depot = 1 full C per depot level
In Kerms region, there is level 1 city (Budweiss), level 1 fort and level 1 depot. If we stick to what is in manual, region should produce: 1 basic SC (for city) + 5 full SC (for fort) + 10 full SC (for depot) = 16 SC. This number is twice as large as Current Supply Level of 8 indicated on in-game tooltip.
Similarly, Wien should produce: 5 SC (city lvl 5) + 10 SC (fort lvl 2) + 40 SC (depot 4 lvl) = 55 SC. However, tooltip say that Current Supply Level for Wien region is 35. I'm not sure how game arrived to 35 and what that number represent.