It’s not part of the keyword I realized, but part of the ability text on some of the Limit/Ransom crew. The +5 crew specifically were what I was looking at.
That last line would prevent that crew from being transferred/unloaded in any way, correct?
Ah, yes in that case.
The 0LR Rerollers don’t have that line, so they could be transferred between friendly ships via exploring with no island involved. I forgot that even has its own specific Code entry:
A zero-point crewmember may be transferred directly to another ship of the same nationality by using an explore action. The “free crew transfer while docked at an island” action cannot be used, because that requires a crew to be unloaded to the island before it is transferred to another ship.