[xwiki-users] Utilities of checking text input in "Page name"?

Hello, What is the function of validation in the text zone "Page name" of /xwiki/bin/create/MySpace/WebHome page? (the green Ok at right side of text zone) In "page name" It seem I can typing any characters (even "aaa$^z*-+/\&é~@ç|-{"#'("   (green "Ok" is displayed ) and validate. AND green "Ok" is displayed even if I type the name of an existing page (of course when I click on "Create", the message "The page MySpace.duplicateName already exists. Please fill in a new page name." appear. Do you think it is a bug a duplicated page test or a reliquat from old versions? Pascal BASTIEN