I've got a scenario for my players where they are going to be working at odds with an opposing team of shadowrunners. As a twist, one of those runners is a contact for one of my players.
I'm trying to give the player a chance at realizing their contact is involved by letting the team's technomancer possibly notice the decker's marks, clueing him in, and allowing the scene to play out very differently.
My thought is that the decker has been scoping the facilities out in advance, and pre-marking objects (they're supposed to do an extraction, and want to be in and out fast). The rules state that marks only last one matrix session, and disappear after reboot. If the decker is operating off a grid they have legal access to, however, and the only hacking they do is to put the mark(s) in place, how might they sustain those marks for, say, a couple of days, without them simply vanishing and not have it be a complete atrocity of overwatch rule-breaking? If this decker was instead a technomancer, then "Clean" could be a way out of my conundrum.