I have changed my pattern username (with the help of Gil Shwartz) so it accept hebrew username.
/^[ '\-_a-zA-Z0-9@\.א-ת]*$/
This pattern suggest it is possible to have an empty name (even if TW will not allow it) so it's better we correct this and put it right with the + sign which forces at least 1 character in the name.
/^[ '\-_a-zA-Z0-9@\.א-ת]+$/
Thanks for raising that issue, Marc.
Aliases or redirections are fine for me, in general, with some addition -> In case a multilingual glossaries (if anybody uses Tiki for that, not me, yet at least), and Spanish and Catalan (or other similar Latin languages) are allowed/used, some issues might arise, because the only difference might be a punctuation character:
Example:
Ambulance (English)
Ambulancia (Spanish)
Ambulà ncia (Catalan)
So, at least, some suggestion might be shown on top (like google does when google "thinks" that you mistyped some char and shows a question: "Did you mean "xxxxx" instead?"