Function.utf8 clean string
From phpBB Development Wiki
utf8_clean_string –– Clean-up a string
Makes a clean string of $text. This function is used to generate a "clean" version of the input string.
Clean means that it is a case insensitive form (case folding) and that it is normalized (NFC). Additionally a homographs of one character are transformed into one specific character (preferably ASCII if it is an ASCII character).
|text (string)||Yes||The text to clean.|
Cleaned up version of the input string
Please be aware that if you change something within this function or within functions used here you need to rebuild/update the username_clean column in the users table. And all other columns that store a clean string otherwise you will break this functionality.
This just explains the function. But is nothing from the phpbb code itself.
which returns "fo0b4r"