Almost every day I have a question about something in the game, and most of the time these questions are not addressed in game nor on the official website. So that leads me to Google, which often brings me to the forum which leads to speculation from many people which then leads to confusion. There should be an easy to use glossary and FAQ as well as updated tool tips to answer these questions. An example, I don't know what half of the enemy debuff icons mean, yet there is no real way (to my knowledge) to find this info out. If it is on you, you can always go to your character description (a bit risky in battle, but at least you can), but this does not exist for an enemy.
Why is this practical/necessary? Sometimes it's important to track debuffs. In the last month I have had to explain to numerous tanks what the symbol is for an enemy being taunted by you is. This is very important information for a tank and for new DDs who may inadvertently be pulling aggro (happens less after ice staff changes, but still happens in pugs all the time). Another example, I created a support frost warden with the intent of having brittle up as much as possible, but I don't 100% know what that icon looks like to track it.
Tl/Dr: is there a comprehensive glossary that exists that explains all the info in game that is never explained in the game?