How does ones game remember which additional HTC Vive Tracker is for which body part?

I am currently working on a program made in Unity that uses additional VR Trackers. I have tutorials on how to include them in the game in general, but how do I save which tracker is for which body part for the next use?

If the user puts 2 trackers on their knees and 1 tracker on their hip, how does the game remember which tracker is for which body part, and also, how can I even set that ingame as a VR User? How can I let the VR User tell the program/game which tracker is ment to be which body part?

 

Havent touched the pucks for a couple years now, but from what I remember you can recognize them by serial number.
I would :
- Create a Setup scene
- Put colliders/triggers on the controller and the VR trackers
- Prompt the user to touch the Hip tracker, then click, or wait X seconds, validate
- Prompt the user to touch the left knee tracker, then click, or wait X seconds, validate
- Prompt the user to touch the right knee tracker, then click, or wait X seconds, validate
- register trackers ID to corresponding Skeletal joints in a config file