Why can't minor suppy base be placed?

[DerAlpman]

In the scenario about St. Vith I couldn't have placed a minor supply base in the city Adler:

adler.png (178.4 KiB) Viewed 547 times

The city has VP, has my units in it and contains a road.

What other requirements must be met?

[nikdav]

You need a "minor city II"

manual75.jpg (243.83 KiB) Viewed 538 times

[DerAlpman]

Are you sure? Because a valid space was the south western hex from Adler. I had troops there, too.

[nikdav]

Sorry but Andler is only a "minor city I " and you need minimum a "minor city II " to build a supply base.

andler.jpg (45.31 KiB) Viewed 521 times

[DerAlpman]

I understood it now. The adjacent city Schönberg is a minor city 3 and the hex I placed the base belongs to it, too.