MIB has 2 meanings
Men in Black
Taken from the movies "Men in Black," "Men in Black 2," and "Men in Black 3" starring Will Smith and Tommy Lee Jones.
I liked the first MIB better than the second and third one.
|POTC||Peck on the cheek|
|LOTR||Lord of the Rings|
|HBO||Home Box Office|
|MST||Must see today|
On online auction and sales sites, MIB stands for "mint in box." This acronym means the listed item is in perfect condition and has not been removed from the box in which it came. Typically, it also means the box has not been opened.
You're most likely to encounter this acronym in listings for electronics and collectibles. Those items' condition can highly affect their value, so sellers use the MIB acronym to denote that the items are in mint condition (and should, accordingly, fetch a higher price).