Blueprinting
No, not printing via Bluetooth but a method of knowing the type of device when discovering devices. I recently found Blueprinting while working on a project.
When phones talk via Bluetooth, it’s sometimes necessary to know the remote phone model so that the appropriate communication or type of content can be sent. It turns out the first three bytes of the MAC address and the service discovery protocol records can be used to determine a phone model manufacturer and model.
There’s also lots of other interesting Bluetooth stuff on the Trifinite site related to security.