In preparation for an article on our national unicycling foundation’s website, I created this overview of unicycling disciplines. The colours show how disciplines (styles) are related. Also, the layout is supposed to (implicitly) show links between disciplines. For example, Flatland and X-Style are close together for a reason. This is a rough version, which I will fine-tune.
Comments? Did I miss anything? Is it perhaps too fine-grained?
Unipacking and Unitouring you could add. Both are unsupported multiple day trips. Unipacking is more Muni like and off-road and unicycle touring more on road.
And you could add Freewheel unicycling. But it hasn’t developed itself as an own discipline yet and if varies a lot where people use it. Most commonly it used so far in Muni and most people who learn it aim to use it in Muni.
And in my eyes Offroad is Muni and by splitting that into Uphill, Downhill, Cross-country, Cyclocross, unipacking and Freewheel you could add my suggestion mentioned above in it. But on the other hand unipacking is also a form of touring.
But great overview so far!
Unitouring is in, under Touring > Multiple Days > Unsupported. That is supposed to include Unipacking, but maybe I need to make that explicit somehow. And like you say, some disciplines (Unipacking is a great example) could fit in two disciplines at the same time.
I think I will add a new category Specialty Unicycles, where Freewheel can fit (along with Ultimate Wheel, Giraffe, Tiny Wheel, and perhaps more). That place in the ‘tree’ would disregard where you would use your freewheel uni.
The term “Muni” is understood by many as a rather technical discipline, contrary to Cross-Country which focuses more on distance and less on technical stuff. But you are not alone in your opinion. I will think about it.
Everyone I know uses Muni to describe (almost) everything offroad, just like the term Mountainbiking is used.
I’d say don’t get too caught up to include everything that is possible on a unicycle - personally I’d tend to throw out some off the things you already have in there - if you want to go more detailed, you can make “sub-maps”.
You are not alone with your first comment, I think I’ll change accordingly.
I posted this on facebook as well (Unicycle Chat) and it generates a lot of discussion/comments. Indeed I will drop some of the finer subdivisions. On the other hand, some others will be added 
Once I have an updated version (may take a few days if only because the comments keep coming) I’ll post it here too.
How about entertainment? Circus or side show acts, juggling, idling, high wire and balance tricks?
From my limited knowledge and experience these are the first things that come to mind:
)Just my 2 cents since I might be completely mistaken at some points 
Yes, when it comes to the required skills you are correct. The reason it is classified in racing are the typical events where those competitions are held, which are mainly track races. Trials riders can do really well in slowraces and especially stillstand, but you wouldn’t normally see those events held at a trials competition. Fun fact: highjump/longjump on the other hand you quite often find at both trials/urban events (EUC for example) and track events.
Unicycle trials mostly has developed as “street trials” - or on very “artificial” courses made from pallets - we don’t really make a difference between street and competition trials, mainly because the competitions aren’t a big factor in anyones riding. And nowadays trials riders in unicycling are more likely to also ride Street/Flatland than Muni, which is why they were put under the “Urban” - category (which is a relatively new word for those three disciplines together I believe).
Cyclocross really isn’t an established discipline in unicycling, they tried it at some competitions (notably a Unicon). The difference to cross country that there are intentionally some sections that you’d have to dismount and carry the unicycle over.
This was also brought up on facebook. I left out entertainment on purpose, focusing on the sports side of unicycling (which can nevertheless range from recreational to world class competitive). But I’ve changed my mind and will include entertainment in the updated version.
Idling is not a unicycling discipline, IMHO, but simply a skill among many others.
Highwire will be included, although it is quite a niche discipline with few practitioners.
I second what finnspin wrote in response to you.
The word “Urban” may be misleading. In unicycling, it doesn’t specifically refer to (happening in) cities.
For Cyclocross I can add that competitive events were held at a few Unicons and European Championships. But I would agree it is more a semi-established competition category than a discipline in unicycling itself. I think no one would classify themselves as cyclocross unicyclist. But as a competitive discipline it is really separate from other muni categories.
As to your question about types of uni used: this is not going to fit in the diagram without making it too cluttered. Possibly this info will find its way into the article that is planned to appear on the website of our national unicycling foundation, for which this diagram is part of the preparation.
Actually Cyclocross is gaining in popularity. Those races can be really fun! In Spain there was huge participation, which made it very interesting riding in traffic throughout the course. And the courses can be very spectator-friendly, something unicycling needs more of. I had a blast at the one in Spain, and the one at the USA Nationals in WA in 2017. As for equipment, it depends on the course but so far I’ve seen a mix of Munis and 36ers. I used my 26" Muni, because that’s what I have, which leaves me the option to choose the correct holes for my pedals. 
Highwire/slackline could be included in the Entertainment section, even though many people do it for hobby, just as they do with a lot of other performing skills. Probably to include a mix of competition and non-competitive “activities”, you might need to do a chart with overlapping circles or something. You can make them look like wheels… 
While most competition events are based on “regular activities”, they tend to get distorted over time, to fit the specific requirements of that competition event. So one possible way to separate things in the chart would be to differentiate competition events from the activities that aren’t competitions, or otherwise the versions of those activities that differ from the competition events. Even then, it will be necessary to note that competition events change and grow over time.
It’s an ambitious endeavor. There will be no perfect way to do it, so remember to have fun with it!
Though I agree what you say about muni, it has become more clear to me that I don’t do real technical muni. What I really do is XC. I like a mix of dirt roads and paved roads with some ups and downs. The steep downhills which require rolling hops or using a break, I mostly find too scary and thus I don’t have those skills.
Maybe you could say Muni is the same as off-road which then does split down in Technical Muni and XC. (Downhills often are technical Muni)
Also is Uphill really a thing? Isn’t just part of any road or offroad rides. What comes down must come up at some point. Naturally with trials you really go uphill or well onto objects to get up. But is there like a specialty of just focussing or having competitions in uphill riding?
Re: uphill muni…
UniNats Australia had a uphill muni race… so yes.
Indeed, Uphill (as a muni discipline) is a regular part of most muni competitions, also on Unicons, NAUCCs, ECUs and more.
The diagram intends (or rather I intend) to map disciplines, not skills or tricks. It would be confusing (quite literally) to mix skills and disciplines.
I watched the uni nat on youtube. Looked quite difficult and tiring for those who decided to hop for 3 metres. Doing small hops like that would be more tiring than taking fewer but bigger hops I guess. Also some peeps with 20-24" didn’t even bother and just walked up. It should be possible to ride up with such small wheels. I reckon we won’t get any uphill competitions for the NKE.
Yes I thought uphill was actually a skill and not a discipline, but yous prove me wrong.
She was the first to respond in this thread
I love uphill riding a lot when riding on my own on my hometrails. When I am about to decide where to go riding, choosing the uphill is often the most important factor. I also really love to challenge myself to beat my previous best times on Strava and to overtake MTBikers on the way up. Having a nice downhill is more like a positive side effect then. And I don’t like walking, so I try to ride everything up because that is mostly easier for me. That’s why so got the nickname “Bergziege” /“Mountaingoat” because when everyone walks I am still riding.
So Uphill is a thing. But I must admit I haven’t found that many people that are enthusiastic about it as I am.
Commuting? 
It is probably how I have used my unicycles the most, except for this year because of Corona and working from home.
