AKC Titles which Labrador retrievers may earn

Titles Appearing Before a Dog's Name
CH Champion FC - Field Champion (Field Trial/Lure Coursing)
AFC Amateur Field Champion
NAFC National Amateur Field Champion
NFC National Field Champion
NOC National Obedience Champion
OTCH Obedience Trial Champion
DC Dual Champion (CH & FC)
TC Triple Champion (CH, FC & OTCH)
CT Champion Tracker
MACH Master Agility Champion

Titles Appearing After a Dog's Name
CD Companion Dog
CDX Companion Dog Excellent
UD Utility Dog
UDX Utility Dog Excellent
TD Tracking Dog
TDX Tracking Dog Excellent
VST Variable Surface Tracker
JH  Junior Hunter
SH Senior Hunter
MH Master Hunter
NA Novice Agility
OA Open Agility
AX Agility Excellent  
MX Master Agility
NAJ Novice jumpers
OAJ  Open jumpers
AXJ Excellent jumpers
MXJ Master jumpers
NAP Novice Agility - Preferred
Open Agility - Preferred

Novice Jumpers- Preferred

Open Jumpers - Preferred

Master Agility Excellent - Preferred

Master Excellent Jumpers - Preferred

Versatile Companion Dog 1 (CD+TD+NA+NAJ)

Versatile Companion Dog 2 (CDX+TD+OA+OAJ)

Versatile Companion Dog 3 (UD+TDX+AX+AXJ)

Versatile Companion Dog 4 (UDX+VST+MX+MXJ)

RN Rally Novice
RA Rally Advanced
RE Rally Excellent
RAE Rally Advanced Excellent

Labrador Retriever Club Titles appearing after dogs name:

WC Working Certificate
WCX Working Certificate of Excellence
both are earned during a hunt test type event (completing land/water marks).
It is designed to show natural ability.