It's supposed to be some kind of convention. Whether it's just for the Voidtrecker Express, or for so-called Void Missionaries as a whole, we don't know yet.

[Ken will be getting more examples as time goes on - or even just if he asks Lightning for her mission notes.]

Your guess is probably as good as ours, even the long-termers. We haven't gotten any big clues yet, and most of those who were looking for patterns just left today.

[Nita sighs, closing her eyes, before opening them again and setting her expression to something a little less... vulnerable.]

This is the last memory, now, and- there's a lot of death, I'll warn you.

No bodies, but it's pretty definite as to what happened.