Not sure how old you are of if you work. However, once you do you'll find that almost every place you go has a sort of own dictionary. Ever listen to doctors and nurses? Police? Firefighters? Sometimes in the news it is difficult to understand what is being said. For example they say things like NRA, or PBS, or HMO, PPO, IRA, K401 and on and on with letters that your supposed to know.
I too find it irritating to have to go to the glossary to find out what is being said. Yet we all do it. And sometimes it gets embarrasing. Once I was at a meeting and everyone kept mentioning PSI. I finally said OK, maybe I'm not to smart but what is PSI. Most would think it's Pounds Per Inch but it turned out to be the name of the clients company. DUH.