Brian Tillman said:
To be pedantic, your latter example contains the letter "y" acting as
a vowel, as it does in the word "rhythm".
"Some users just check for "a", "e", "i", "o", "u" and a number, ..."
See, no "y" there. Some forget to add "y" and only list the main 5
vowels, and think checking for these will encompass enough of the words
or text strings that might be used in a sentence.
Shhh
nth
Mr.
Mrs.
TV
pfft
psst
tsk tsk
'n
hmm
If you permit more languages than just English then there are lots of
words without vowels (because what is written is different than what is
spoken). I've read that "lm" or "lmh" is "Alma" and "YHWH" is
"Y[a|e]hweh" in Hebrew. In Welsch, "cmm" is "koom", "bws" is "bus", and
"yw" is "you". Even using the above short list, you could have a
subject of "Tsk tsk. Mr. 'n Mrs. TV, hmm?"