In v3.1, civilian colony ships pick up colonists from populations of less than 20m and drop them off at populations of 20m+. I wanted to allow a little more flexibility without giving control over civilian ships to the player. Therefore, for v3.2 any population of less than 25m is automatically a destination for civilian colonists and any pop over 25m defaults to being a source of colonists. However, for those pops over 25m you can change them on an individual basis to being a destination for colonists rather than a source of them. This means that the small colonies will still get plenty of civilian traffic but gives you the flexibility to allow larger colonies to receive civilian traffic too, possibly because they are a key colony or maybe because there are no small colonies and you don't want to have civilian ships sat idle (and neither will the civilian owners). A population cannot be both a source and a destination so civilian colony ships will not pick up from large colonies set as destinations.
Steve
