The place in your work/school/house that you feel most comfortable defecating(taking a poo).
In colleges or work this is the bathroom that is usually the cleanest, and least visited bathroom. No matter what time of the day you can take a dump comfortably without worrying about your friend coming in and recognizing your shoes. You usually get so comfortable that you find yourself surfing the web or even dozing off in your HQ loo.
In homes the only thing that is different is that it is where you keep all your miscellaneous items. So that you can make the poo experience more enjoyable. For examples magazines, puzzles, or even a tv.
You get a text from your friend
Friend: Where are you? There are free donuts in conference room!
You: Aw man, get me one I'm in my HQ loo!
Friend: looks like your sh*t out of luck...no pun intended