The joke that is the "Clarity" design value
So six months ago, Riot made a big post on Clarity. Since then, many aspects of the game have remained unclear, and many new things have been added which are unclear. I want to take a look at some of my favorite examples, and will likely edit this post to include good ones people leave in the comments.
We absolutely welcome your feedback on all of these points – and call us out when we fall flat!
Gladly. Lets get started.
Cleanse
"Removes all disables and summoner spell debuffs affecting your champion and lowers the duration of incoming disables by 65% for 3 seconds." - Riot Games
Does not remove or reduce Suppression (a disable), knock-ups (a disable), knock-backs (a disable), grabs (a disable) and flings (a disable), or the Grievous Wounds inflicted by Ignite (a summoner spell debuff). The description flat out lies to players, and needs to be fixed.
Death Recap {{summoner:10}}
If you've played the game enough, you've probably noticed that Revive has an unlisted ability to do damage, even when no one in the game took it. That or the death recap lies to you.
The problems plaguing the Death Recap screen are numerous and have their own topics. It's sufficient to say that its current state is probably among the worst clarity offenders. "Mixed Damage" is incredibly vague (how much was Physical/Magic/True/Pure/Other?), champions assisting in their own death (but not getting the gold for it), damage not totaling correctly, etc. This needs to be fixed.
Summoner Spells in General
There is no way to tell how long the cooldown on a summoner spell is before you get into a game. Using the resources Riot provides, a player must enter a game with a summoner spell and mouse over it to see the cooldown. They must remember the answers to questions like "Does Barrier have a shorter cooldown than Heal?" for the rest of their time playing.
Airborne 
"Adjective - flying; in the air" - Dictionary
"Something potentially including but not limited to the dictionary definition" - Riot Games
"Airborne" is never defined on the League of Legends website "Game Info" section, client, or game. To figure out the Riot Games definition of Airborne, players must buy Yasuo, then proceed to pay close attention to every champion and spell in the game. In doing so, they'll realize that champions like Anivia and Kayle, who are always flying, are not in fact "Airborne". Dragging someone across the ground however renders them "Airborne". Someone having a pillar of ice rise up from under their feet, making them sidestep, renders them "Airborne".
The better word to use here is "displaced". If you're going to use Airborne, make it match the definition given by a dictionary or define it yourself somewhere.
Unstoppable vs. Wall

This one should never have been allowed to happen.
Azir is released. It's stated multiple times that his wall will not stop unstoppable movement. One particular examples in the game is Malphite's Unstoppable Force, which is referenced in the Champion Spotlight video.
Two patches later Sion is reworked, with an ultimate called Unstoppable Onslaught that stops early if he hits a wall.
This is an Unbreakable Shield means a Spear that can pierce anything scenario. This is horrible from a clarity stand point, and the worst part is that to get around it all you needed to do was replace the word "Unstoppable" from the name of Sion's ultimate. Either fix Sion so he can charge through Azir's Ultimate or rename Sion's ultimate.
Poison vs. Poison

Cassiopeia's Twin Fangs says "If the target is poisoned, the cooldown of this spell is refreshed", but neglects to mention that it's only counts for three other champions, Teemo, Singed, and Twitch.
"Gangplank's basic attacks and Parrrley apply a poison [...]" - Passive description on website and game.
"Two-Shiv Poison" - name of Shaco's E ability.
Gangplanks can be changed with a simple tooltip, but I have no idea how Riot intends to work around the lack of clarity with Shaco's E.
Wild Card 
Even if you've never played as Twisted Fate or read his description, you catch on pretty quick that the different colors of Pick a Card do different things. It's also easy to see that the colors of the Pick a Card are re-used in Wild Card. As a new player, I was terrified of Wild Card because I was convinced that the different colors on the cards meant they had different special effects. You can imagine how desperate I was to dodge when I saw three yellows heading my way.
As bright and as fun as the Wild Card colors are, they probably need to be changed for clarity's sake.
Ability Descriptions: Colors
Orange, Green, Blue, Pink, Yellow, Red, and probably others I'm forgetting or don't know about. Take a new player and ask them what any of the mean and you'll probably get a shoulder shrug. Take someone who mains one type of champion and ask them about the others and they'll likely get them confused too.
If you don't know what the colors mean, how in the world can you be expected to buy items that have stats that boost your abilities?
A possible fix here is in the store. If you highlight "Ability Power" in green, it will be at least a little clearer that items bought here will increase the stats of any ability with green text.
Ability Descriptions: Scaling
Lets say a champion had an ability that scaled 5% off of AD and 200% off of AP. What hint does the Client or Game give that you should build AP instead of AD? You start out with a bonus from AD and 0 bonus from AP, implying that AD is the stronger scaling stat because it at least gave you something.
While the League of Legends website does list scaling on abilities, the website is horribly slow and inconsistent in updating. Right now every champion in the game has +X Per Level base stat boosts, instead of the growth modifier that was introduced in 4.20, which was released over a month ago.
When fan-made Wiki's get updated to have more correct champion stats than Riot's own website, players can not rely on on Riot's website. Add the percentages to the Client/Game, update the website to be accurate.
New: Snared, Entangled, Rooted, Bound
Are there differences in what these effects actually do? If so, I haven't noticed them, so they probably need to be emphasized more. If not, these names can probably be replaced with just one word to describe the crowd control.
(Thank you ShardWintreswolf)
Conclusion
Like I said, I'm sure there are more that I'm forgetting, but these things stick out like a sore thumb to me. I have a hard time believing that Riot actually believes in clarity, and will continue to until these issues are 1) talked about and 2) at least a rough timeline is given for when we will see them implemented.
Feel free to leave any other offenders in the comments. I'd very much like this thread to be the to-do list for the "Clarity" team.
Q and
ult.
Many people think her ultimate is OP because she is invulnerable while using it, which is not true. She is still affected by DoTs and AoE damage. Additionally, her Q makes her ignore collision while traveling to the target, which includes skill shots.
I've been playing a lot of Morde lately and one thing that bothers me is his ult's description. "The ghost's stats are enhanced." Enhanced how? It very clearly explains the buffs Morde receives if his target dies, but not the buffs of his pet.
It does state how much base health you gain with 0 fury, but it could probably be a little clearer. I see people all the time who won't use it when they are low health and I could not figure out why. Then it hit me, the description says "consume fury" and they had none.
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