Welcome
I have been thinking about making something this for a very long time, because I am a bit annoyed with the currently available wiki putting any and all Harry Potter-related content on the wiki as fact. The HP Lexicon was my faithful companion for many years but I have my own interpretations of the text (obviously, everyone does) and as such, I sometimes disagree with it as well. The only way to fix this, however, is to make my own, so voilà, here it is, my very own Harry Potter encyclopaedia ... thing I have decided to call it my Headcanonopaedia, because I am unoriginal like that. Just for the sake of clarity, that means that this is the Headcanon version, with content from my fanfiction-universe, but I also have a Canon version available, which contains just the content from the seven Harry Potter books, as well as other canon (the sources will be clearly marked), so that I can keep my own ideas and canon fully seperate. At least, I intend to. Feel free to use either as much or as little as you want!
Using This Headcanonopaedia
This Headcanonopaedia works just the same as the Canonopaedia. It has the same structure and layout. At the top of every page, however, you will also see a disclaimer that you are on my Headcanon-version, with a link to the corresponding Canon page, to hopefully avoid confusion. The main treason that these pages are so very similar is that this is my real project: a collection of information that fits the wizarding world as I imagine it for my fics, which all take place in the same universe, by the way. But since my universe is heavily canon-compliant, aided by my obnoxious autism, it is quite easy to adapt the pages so that just the canon content remains, which then goes on to become the Canonopaedia, and can be useful to others. Of course, you are more than welcome to use this Headcanonopaedia as well, but just keep that in mind. I also have not taken as great measures to distinguish different tiers or include sources on this version because that would only get in the way, or so I feel. This version is definitely a lot more laid-back! Now, here is the same introduction as on the other page, for your convenience:
Unforturnately, I have not (yet) been able to make this site searchable in a way that wouldn’t include my fanfics as well, so you’ll have to make do with this. Hopefully this little guide will help you on your way. So, on the left side (or top, if on a small screen), I have made a list of, well, lists, to help you navigate to the page you need. For example, if you want to know how old Lucius Malfoy is, you go to ‘Characters’ and search for ‘Lucius Malfoy’, or manually scroll down until you find him. On his character page you’ll find his age and possible date of birth, among other things. All these individual pages are searchable through your device, and I have made the lists searchable as well.
Now, you will soon see that every individual page/article has the same format. First you will get a short overview/fact-file à la Pottermore, where you can see date of birth, parentage, hobbies, but also where the character (or object, or location, or whatever) was first mentioned, defining characteristics, etcetera. Below that is a short overview and then a timeline of events canonically involving the subject of the page. Every list also has the same layout, with most sorted alphabetically for your convenience. Timelines all follow the same structure as well, so you should be familiar enough with the way this site works before long.
(If you’re reading this, chances are you know who I am, so if you want anything in particular added, just let me know!)
Canon and Headcanon
If you want a clear overview of what I see as canon overall, you should check out my Canon companion page, because I will only work with the words ‘Canon’ and ‘Headcanon’ here. ‘Canon’ is a bit more nitpicky than what I include on the other page, because on there, I try to be considerate of people who, for example, really like Cursed Child, and so I do include information from there, even though I do not consider most of it canon. On here, that information that I do not consider canon is simply missing, and I don’t give any explanation why, because, as explained above, this is for my own enjoyment and serves as a sort of wiki for my own fanfiction universe more than a true encyclopaedia of the Harry Potter series. Therefore, I’ll just put a marking saying Canon (C) or Headcanon (HC) behind a piece of information. If it says that it is canon, you are always free to go to the Canon page if you want to know more, of course. But yeah, That is how things are going to work around here.