Currently when immigrants come to your fortress, there's a good chance they will come with giant cave spider silk clothing, which is outrageously valuable. I've seen the imported goods level go from 20k to 100k from a few immigrants, and killing off those dwarves can let you buy out trade caravans.
The proposal is to disable this. No more starting dwarves with giant cave spider silk clothing, and no immigrants with it either.
I don't know why they have it currently, it seems it should be rare seeing how vicious giant cave spiders are. :roll: