Because of the endless waves of confusion, here’s the most common acronyms used in the Lounge (YMMV). Feel free to expand (no such thing as notability — but try not to invent new ones that nobody ever used).

If in doubt, you can look-up acronyms at TheFreeDictionary. Note that the list is not necessarily sorted.

Generic chat acronyms

Acronym Expanded
AFAICS As far as I can see
AFAIK As far as I know
AFAIR As far as I can remember
AKA Also known as
FTFY Fixed that for you
FTR For the record
FYI For your information
ICBW(T) I could be wrong (though)
IIRC If I recall correctly
IIUC If I understand correctly
IME In my experience
IMO In my opinion
IMHO In my humble opinion
IOW In other words
IANAL I Am Not A Lawyer
IMNSHO In my not so humble opinion
ISTR I seem to remember
ITT In this thread
IYAM If you ask me
NSFW Not safe for work
NWS Not work safe
NMS Not mind safe
OT Off Topic
OTOH On the other hand
RTFM Read the fucking manual
SCNR Sorry, could not resist
PEBKAC Problem exists between the keyboard and the chair
TIL Today I’ve learned
TTBOMK To the best of my knowledge
WRT With regards to
YMMV Your mileage may vary
BBIAB Be back in a bit

C++-specific

Acronym Expanded
CRTP Curiously Recurring Template Pattern 1
ICE Internal compiler error 2
ICE Integral constant expression
MVP Most vexing parse 3
NVI Non-virtual interface pattern 4
ODR One Definition Rule 5
RAII Resource Acquisition Is Initialization 6
RTTI Run-time type information 7
SBRM Scope-Based (or Scope-Bound) Resource Management, see RAII
SFINAE Substitution failure is not an error 8
UB Undefined behaviour 9
UDL User-defined literals
UDT User-defined type
  1. https://en.wikipedia.org/wiki/Curiously_Recurring_Template_Pattern

  2. https://en.wikipedia.org/wiki/Compilation_error#Internal_Compiler_Errors

  3. https://en.wikipedia.org/wiki/Most_vexing_parse

  4. https://en.wikipedia.org/wiki/Non-virtual_interface_pattern

  5. https://en.wikipedia.org/wiki/One_Definition_Rule

  6. https://en.wikipedia.org/wiki/Resource_Acquisition_Is_Initialization

  7. https://en.wikipedia.org/wiki/Run-time_type_information

  8. https://en.wikipedia.org/wiki/Substitution_failure_is_not_an_error

  9. https://en.wikipedia.org/wiki/Undefined_behavior