What do all the letters mean?

Breed Titles:
Am Ch: American Champion
Cdn Ch: Canadian Champion

Obedience Titles:
CD: Companion Dog
CDX: Companion Dog Excellent
UD: Utility Dog
OTCH: Obedience Trial Champion (highest level)

Agility Titles:
NA: Novice Agility
OA: Open Agility
ADX: Agility Dog Excellent

Flyball Titles:
FD: Flyball Dog
FDX: Flyball Dog Excellent
FDCH:  Flyball Dog Champion
FDM:  Flyball Dog Master
FDO: Flyball Dog Onyx

Retrieving Titles:
NRD: Novice Retrieving Dog

CGC:  Canine Good Citizen