Vowels in this context refers to: a e i o u y (including upper case)

That's already there. If any other variation (like á, à, ä or whatever) would be allowed, it should be stated, but imo it's clear as it is.

Please specify that it's only about ASCII vowels.

Maybe not for you and your part of the world, but it is for me and my part of the world. And, apparently, y is a vowel for the author and the author's part of the world.

Y is not a vowel.

Java translation

"commonly agreed" must be something i am not English enough to understand. In my language, Y is always a vowel.

Is it really that bad to treat Y as a vowel in this task if it is so clearly and explicitly specified? Would removal of Y help anyone in any other way than now they would not have to read the description carefully?

Most of the time it is not used as a vowel. It is only a vowel in words such as 'why', but in words such as 'yes' it is not. An acceptable solution to the Kata allows the letter y to be classified as a vowel in both cases, which is incorrect. In order for the Kata to be correct, it needs to be reclassified as being significantly harder as it would need to consider the structure of words for common patterns of where y is a vowel and not a consonant. Or, remove yas a vowel and stick with the commonly agreed a, e, i, o and u.

Why y is considered as vowel ???

@KUN7DM, when you used the word why in your comment, the letter y was being used as a vowel. In English, the reality is that most of the time y is used as a vowel, although most English speakers do not actually know this.

why not? In some countries it is, in others it ain't

why is 'y' a vowel....

You may well have found good evidence backing your claim, but I categorically refuse to look at anything that could potentially start to undermine my irrational beliefs. Instead, I will retreat further into my shell by only recognizing Y as either a vowel or semi-vowel. The concept of Y as a consonant be banished!

Call me obstinate, call me an ideologue, call me an obstinate ideologue, or call me a twat. You probably wouldn't be too far off with any of these characterizations, but one thing is for sure, you Y-Consonanters have had your day!

You can have fate on your side, but I have just stumbled upon this conclusive proof that Y is in fact a consonant: https://www.codewars.com/kata/5a19226646d843de9000007d

Read it and weep, fellow Y consonant users have coalesced and produced this brilliant counter kata. I have also decided that the solution to this issue is for me to avoid all suspicious usage of Y as a "vowel" henceforth. I think you will find this response adequate in this regard, and I'm quite enjoying being forced to re-evaluate the words I use. Yet, a single perfect tear leaves its mark upon mine face as I see how beautiful the english language can be without this fake vowel. Perhaps this issue should be taken to a higher judicial level, and all Y vowel words must be purged from our lexicons. I shall not miss them.

Valiant you may be, but I'm afaid your cause is lost as I have destiny on my side seeing as it can be no coincidence that VICTORYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY!!! is spelled with a vowel Y