OCS stands for Orthopaedic Certified Specialist. It means the therapist has taken a special test and passed. The American Physical Therapy Association (APTA) gives the test. It's used to identify "experts" in orthopedic problems like neck and back pain.
FAAOMPT stands for Fellows of the American Academy of Orthopaedic Manual Physical Therapists. This group of therapists has done extra training in the area of orthopedic manual physical therapy.
A residency or fellowship program is required. Manual therapy is a hands-on approach to restoring joint motion especially in the spine.
When looking for a physical therapist to meet your needs, don't be afraid to ask about years of experience and level of training. This doesn't always guarantee a level of expertise but it helps.
Training is one thing but bedside manner is still very important to many people. Once you find a therapist with the kind of training needed for your problem, then you can narrow down the one you can work with based on your personality and goals.