A thought exercise for those pondering all things ownership: When you wake up in the morning and boot up your commlink, how does your gun know you're its owner? Does being a technomancer change things?
It knows, because the game says it knows.
Now, If you really want it, I am sure the writer of that section of the rules would happily write out a 300 page manual explaining all the ins and outs of the system and how it all interconnects for you... for the low low cost of a few thousand dollars. (That's what I and my company charge when asked to write out detailed manuals for control systems we install, if a working engineering schematic was not provided to us).
Or, you can accept that, as Todd Howard says: "It just works".... because the game system says it does.....
And I suggest you search the forums for Ownership to see where THIS conversation is going, as it covering ground that has been brought up a dozen times before.... (and hopefully no one gets hit with the ban hammer this time).
But, yes, it works because the game system says it works, and it works in the basic way myself and others have put forward. It's all one giant confusing mess tied to a SIN, because the SIN is the very base piece of info you need. Its the cornerstone of the matrix, by the very basic mess of "without a SIN you can't get access to the matrix" <Barring black site access provided by Organized Crime, Fuchi, and Shadow Brokers> It's all there in the books if you dig deep enough. Its just not spelled out in an "A to B to C" fashion, nor is it done in the minute detail some want.