This is a really short one. A pet hate of mine is when people use acronyms and jargon without explaining what they are when they are talking with people they don't know.
Jargon can be a way of demonstrating to others that you know what you are talking about without actually saying anything.
The flip side - jargon can also be a way of expressing complex ideas quickly, because there is a shared context of what the phrase means if you unpack it.
So, if like me you hear people use jargon and you don't always ask what it means, I present the: