You can change the spin direction of such particle through spin manipulation (e.g. using magnetic fields) and that would change the spin of the entangled particle too. This way you can codify messages using binary code, since you now essentially have a switch that has two states (e.g. up=0, down=1).

This way one can send information faster than c, including the message "new entangled particle, who dis?”, so the receiver of the particle doesn't need to know a priori that the particle is entangled.