I have an acronym in my story, ALNC, which is the name of a group of friends. The only people who know what it means are those friends. I don't ever reveal it to the reader.
Is there anybody else who does something like this? Just curious :)
Yes!
When I was first coming up with my story (it was yeeaaars ago), I could NOT stick with a name for my main character. So I called him X while I wrote. Then X just STUCK and it was even harder to call him anything else! I talked about him with everyone for years, referring to him as X, and I was so close to just making that his name. I finally settled on Asher, since I just wanted to settle. But I decided that his first name's initial would be X, and his middle name would be Asher. No reader will ever find out what the X stands for when reading the books, and I won't tell 'em because I have no clue.