Goods and Minerals.

There are 3 types of item that can be traded:

Free floating Goods and Minerals

Goods and Minerals can end up floating in space:

Floating objects can be picked up by ramming them.

Floating objects a limited lifetime. If not picked up (or destroyed) they self-destruct.

Dumping cargo

If NOT docked goods/minerals can be 'dumped'. This will leave them floating in space.

This is useful if you end up carrying illeagal goods or want to clear out space in the bay. You can't 'dump' in dock ... it would make a mess on the floor!