How about a pinned message with a glossary? If people post their definitions here, I will assemble the pinned post from the entries.
I agree this may come in handy for folks who are newer to the forums, provided of course that they manage to find it. I put together a few of the more common abbreviations and terms to get things started. We'll see where it goes from here if there's any more general interest in adding to the list. Sorry it's not in any particular order, but it may do to at least start with.
Below are some of the more common terms and abbreviations used on the WitP AE forum. (Note that these do not include abbreviations for ship types, which are already listed separately in the manual. While most people who buy this type of game are familiar with more common abbreviations like BB for Battleship or CV for Fleet Carrier, the forums are full of people asking questions or commenting on the abilities and uses of ACM, AE, AMc, xAKL, etc. It's worth taking a few minutes to learn what each of these (and other)ship types are used for or intended for by reading the manual.)
RTFM - Read the F---ing Manual. In this forum, usually used self-deprecatingly by someone who asks a question that's been asked many times before without looking to see if the answer is already at their fingertips in the manual. Fortunately it's rarely used on the forums as a real answer.
TF - If you don't know this abbreviation, you probably need to RTFM . (If you really don't know this one, it stands for Task Force - a collection of ships grouped together for a single purpose. Also, if you didn't know this one, the manual really is a must-read before being able to make any kind of sense out of the game.)
AFB - Allied Fanboy. Someone who plays mostly or exclusively as the Allies.
JFB - Japanese Fanboy. Someone who plays mostly or exclusively as the Japanese.
DEI - Dutch East Indies. The territory held by the Dutch at the beginning of the game. Java, Celebes, Sumatra, much of Borneo, etc. Rich in resources and oil. Also referred to as the SRA.
SRA - Southern Resource Area. Area encompassing mostly the Dutch East Indies, rich in both oil and resources. More or less the same as the DEI when referred to in game.
HI - 1. Heavy Industry. Production points generated by Japan, and used to build aircraft, engines, ships, tanks, etc.
2. Home Islands. The Japanese main islands of Honshu, Kyushu, Shikoku, and Hokkaido (plus a couple of other tiny ones.)
3. Hawaiian Islands. (Note: This usage of HI on the forums is rare, but it is occasionally used.)
PI - Phillipine Islands. Luzon and Mindanao are the main islands, but the term refers to the entire archipelago.
ASW - Anti-Submarine warfare, or referring to assets (either naval or air) involved in anti-sub activity.
FOW - Fog of War. Referring to situations, where the game won't always give you a complete or accurate view of combat, enemy troop composition, sunk ships, spotting, etc.
OT - Off topic. A thread not immediately related to the game, though usually related to the period. (Unless it was started by Footslogger, then all bets are off.)
LBA - Land-based aircraft. Planes flying from a base versus from a carrier.
KB - 1. Kido Butai. Japanese carriers, operating all together in one large task force. Early war, you'll see many references to staying away from the KB, or making sure as the Allies you know where the KB is, or "my LBA refused to attack the KB!!"
2. Kota Bharu, usually one of the first Allied bases invaded in the war, located at the top of the Malay peninsula.
SCTF - Surface Combat Task Force. A group of ships put together to engage enemy ships, or to screen friendly ships in a separate task force. (also frequently referred to as a SAG.)
OOB - Order of Battle. A list of the forces one side has (or will receive) for any given scenario.
LCU - Land combat unit. Divisions, regiments, brigades, etc.
HR - House Rule(s). Any agreement between players in a PBEM (play by email) to amend or change rules, generally intended to prohibit certain tactics which game mechanics may allow, but which both players feel are not beneficial to the type of game they wish to play. Often used to try to make campaigns play out closer to "historical" results.
DL - Detection level. How visible (or not) either your forces, or your enemies forces are (often influencing the likelihood and accuracy of attacks.)
VP - Victory Points. Points which measure each players relative success, and which determine the levels of victory and defeat in scenarios and campaign games. Note: You can't "spend" victory points on anything, you only gain or lose them over the course of the game before an outcome is determined.
PP - Political Points. Points given out every turn which can be "spent" by making discretionary decisions in game, such as changing out inferior leaders for better ones, changing the HQ affiliation of some units to allow them to freely travel to other theaters, changing aircraft types in a given squadron, etc.
AF - Air Field. Usually referring to the size of an airfield at a given base, as in "Manila just hit AF4".
DBB - Da Big Babes. One of a series of popular mods for WitPAE. Designed by many of the folks responsible for creating WitPAE in the first place.
RA - Reluctant Admiral. Another well known mod for WitPAE.
CBI - China, Burma, India theater.
PH - Pearl Harbor.
SF - San Francisco.
Oz - Australia.
WC - West Coast (of North America.)
EC - East Coast (of North America.)
HK - Hong Kong.
CT - Capetown.
IO - Indian Ocean.
SR - Service rating. A reliability rating given to each type of plane, from 1 to 5, with 1 indicating the aircraft is very reliable and 5 indicating that the plane type has serious and frequent maintenance needs. Greatly impacts how many planes in a given group will be ready fly if they've been recently been used.
SIGINT - Signals Intelligence. Radio intercepts, code-breaking, etc. which may give you some information about what your opponent is up to. In game, this information is located on the Intelligence Report.
Sandbox - A test scenario, where conditions are set and then run multiple times to help determine what effect certain variables in the game actually do. Often used as a verb, as in "I sandboxed a CV battle in late 42 where the Allies had limited help from LBA."
Sir Robin - Early war Allied strategy involving various degrees of fleeing from Japanese advances instead of fighting back, with the goal of minimizing losses and husbanding strength for a later counter attack. (From Monty Python's "Holy Grail", "Brave, brave sir Robin, he bravely ran away!!" as sung by Sir Robin's minstrels, before they eventually ate Sir Robin's minstrels.)
Ablative armor - The use of obsolete airframes as escorts to draw fire on themselves, thereby shielding the bombers they are escorting from attack. Occasionally used by Japan as a late war tactic.
Restricted - Refers to the freedom of mobility (or really the lack thereof) for both LCUs and air groups. Unrestricted groups can travel or transfer to and from any base you own. Restricted units are limited to the theater they start in (West Coast, Home Defense(Japan), China, etc.) unless a player spends PPs (see above) to free these units up. Note that there are some cases where units cannot be freed up by any means - these would be referred to as Permanently Restricted.