I’ll use the cliche meme of “I was today years old when I learned where the name comes from”. Just made the connection when I read this article, and I love Pulp Fiction.
But I too am not a native English speaker. Just always accepted the clunky acronym as the reason for the name.
Dunno if you’re German or Austrian or something, but in Vienna there is a Ziegelmuseum whose curator studies the history of bricks, how they were made and used and whatnot. They have a long list of brick makers in Austria, when they were active and so on.
If you’re in another country, they could maybe help get you in contact with a historian local to you.
Could help you learn more about your mystery brick.