​Please see:

Tips for owners:
http://www.lostdogsflorida.org/important-microchip-tips-for-pet-owners.html

Tips to track down an unregistered or "dead end" microchip:
http://www.lostdogsflorida.org/tracking-an-unregistered-or-dead-end-microchip.html

Tips for shelters and vet clinics:
http://www.lostdogsflorida.org/microchip-info-for-shelters-and-vet-clinics.html