This is a work in progress...
A
AB: Anheuser Busch
AB-InBev: Anheuser-Busch InBev
AC: Apollo's Chariot
ACE: American Coaster Enthusiasts
AI: Adventure Island
Alpie: Alpengeist
AP: Annual Pass
AT: Amusement Today
B
B&M: Bolliger & Mabillard
BEC: Busch Entertainment Corporation (Defunct)
BBW: Big Bad Wolf (Defunct)
BG: Busch Gardens
BGA: The Worlds of Busch Gardens Africa (See BGT)
BGE: The Worlds of Busch Gardens Europe (See BGW)
BGT: Busch Gardens Tampa (See BGA)
BGW: Busch Gardens Williamsburg (See BGE)
Bolt: Verbolten
Bolty: Verbolten
BSG: BlackStone Group
BTR: Batman: The Ride
C
Caro: Carowinds
CCI: Custom Coasters International
CF: Cedar Fair
CGA: California's Great America
CH: Cheetah Hunt
CM: Cast Member
CP: Cedar Point
CT: Christmas Town
CTC: Cut Throat Cove
CW: Colonial Williamsburg
CW: Canada's Wonderland
D
DAK: Disney's Animal Kingdom
DC: Discovery Cove
DCA: Disney's California Adventure
DD: Dueling Dragons (Defunct)
DF: Drachen Fire (Defunct)
DHS: Disney's Hollywood Studios (See MGM)
DIU: Dig-It-Up
DK: Curse of DarKastle
DL: Disneyland
DLP: Disneyland Paris
DP: Dorney Park
DW: Dollywood
E
EfP: Escape from Pompeii
EitA: Europe in the Air
ERT: Exclusive Ride Time
EG: Elitch Gardens
E-Ticket: A large ride/attraction that has a significant draw and likely anchors an area.
F
FEC: Family Entertainment Center
FL: Fast Lane
FoF: Sesame Street: Forest of Fun
FOF: Flight of Fear
FUN: Cedar Fair (NYSE)
FT: Six Flags Fiesta Texas (See SFFT)
G
G's: Gravitational Force
GCI: Great Coasters International
GG: The Gravity Group
GL: Geauga Lake
GP: General Public
GR: Guest Relations
H
Haunt: Halloween Haunt
HHN: Halloween Horror Nights
HoS: Howl-O-Scream
HP: Harry Potter
H:RRR - Hollywood: Rip Ride Rocket
I
I305: Intimidator 305
IAAPA: International Association of Amusement Parks and Attractions
IAD: International Amusement Devices
IOA: Islands of Adventure
IOE: Irvine-Ondrey Engineering
Industry: The Themed Amusement Industry
IPO: Initial Public Offering
J
JCC: James City County
K
KBF: Knott's Berry Farm
KD: Kings Dominion
KI: Kings Island
KK: Kentucky Kingdom
KK: Killarney Kommotion
KW: Kennywood
L
LIM: Linear Induction Motor
LNM: Loch Ness Monster
LotD: Land of the Dragons
LR: LaRonde
LSM: Linear Synchronous Motor
LV: Las Vegas, Nevada
M
MA: Michigan's Adventure
MCBR: Mid-Course Brake Run
MGR: Merry-Go-Round
MGM: Disney's MGM Studios (See DHS)
MIU: Mix-It-Up
MoA: Mall of America
MK: Magic Kingdom
MT: Mach Tower
N
NAD: National Amusement Devices
NAPHA: National Amusement Park Historical Association
Nessie: Loch Ness Monster
NL: No Limits
NL2: No Limits 2
NTG: New Texas Giant
O
OP: Original Post (First post in a thread)
OTS: Off The Shelf
OTS: Over The Shoulder
OTSR: Over The Shoulder Restraints
P
PF: Park Fan
PFN: ParkFans Network
PKS: Premier Parks (Defunct)
POP: Pay One Price
POV: Point Of View
PR: Public Relations
PTC: Philadelphia Toboggan Coasters
PS: Planet Snoopy
Q
QQ: Quick Queue
R
RC: Roller Coaster
RCCA: Roller Coaster Corporation of America
RCT: RollerCoaster Tycoon (Computer Game)
RCT2: RollerCoaster Tycoon 2 (Computer Game)
RCT3: RollerCoaster Tycoon 3 (Computer Game)
RCTW: RollerCoaster Tycoon World (Computer Game)
RMC: Rocky Mountain Construction/Coasters
RoAE: Root of All Evil
Root: Root of All Evil
RPT: Royal Palace Theater
RR: Roman Rapids
RRR: Hollywood: Rid Ride Rocket
S
SBNO: Standing But Not Operating
SDC: Silver Dollar City
SEAS: SeaWorld Entertainment (NYSE)
SF: Six Flags Theme Parks
SoF: Sesame Street: Safari of Fun
SFA: Six Flags America
SFAW: Six Flags AstroWorld(Defunct)
SFDL: Darien Lake
SFDK: Six Flags Discovery Kingdom
SFEG: Six Flags Elitch Gardens (See EG)
SFFT: Six Flags Fiesta Texas (See FF)
SFGAdv: Six Flags Great Adventure
SFGAm: Six Flags Great America
SFHH: Six Flags Hurricane Harbor
SFKK: Six Flags Kentucky Kingdom (See KK)
SFM: Six Flags México
SFMM: Six Flags Magic Mountain
SFNE: Six Flags New England
SFNO: Six Flags New Orleans (Defunt)
SFO: Six Flags Ohio (Defunct)
SFoG: Six Flags Over Georgia
SFoT: Six Flags Over Texas
SFSL: Six Flags Saint Louis
SFWoA: Six Flags Worlds of Adventure (Defunct)
SLC: Suspended Looping Coaster
SOB: Son of Beast
SOP: Standard Operating Procedure
SP: Sesame Place
SWCa: SeaWorld California (See SWSD)
SWP&E: SeaWorld Parks & Entertainment (See SWPE)
SWPE: SeaWorld Parks & Entertainment (See SWP&E)
SWFL: SeaWorld Florida (See SWO)
SWO: SeaWorld Orlando (See SWFL)
SWSA: SeaWorld San Antonio (See SWTx)
SWSD: SeaWorld San Diego (See SWCa)
SWTx: SeaWorld San Antonio (See SWSA)
T
TiO: This is Oktoberfest
TM: Team Member
TOGO: Kabushiki-gaisha Tōgo
TOT: Tower of Terror
TR: Trip Report
TTD: Top Thrill Dragster
U
UOR: Universal Orlando Resort
USF: Universal Studios Florida
USH: Universal Studios Hollywood
USO: Universal Studios Orlando (See UOR)
V
VB: Virginia Beach
VBolt: Verbolten
VF: Valleyfair
W
WC: Water Country USA
WCUSA: Water Country USA
WDW: Walt Disney World
WoF: Worlds of Fun
WWHP: Wizarding World of Harry Potter
X
XSF: SkyFlyer: Xtreme Skyflyer (KD)