We allow most individuals and their ships access to our stations, so long as they dont cause trouble. However, to respond to your cardamine example - that we do not allow. Vessels hauling cardamine, synthetic marijuana, or other high contraband goods will be denied docking access and told to take their cargo elsewhere.
We are trying to keep a nuetral-friendly stance with the local law, and the rheinland federal police and military do not tolerate contraband in the least. If they found out that we were actively allowing such contraband to move through our stations, they would not hesitate to send a fleet of bombers out to kreuzberg or bornholme and blast the station to space dust.
So, in the interest of the station and it's inhabitants, no contraband is allowed.