Which characters can I use for complex passcodes? I need to know which characters I can use in a (complex) passcode for iOS
I'm not 100% sure, and couldn't find much online but I'm guessing something like:


Uppercase characters of European languages (A through Z, with diacritic marks, Greek and Cyrillic characters)
Lowercase characters of European languages (a through z, sharp-s, with diacritic marks, Greek and Cyrillic characters)
Base 10 digits (0 through 9)
Nonalphanumeric characters: ~!@#$%^&amp;*_-+=`|(){}[]:;"'&lt;>,.?/
Any Unicode character that is categorized as an alphabetic character but is not uppercase or lowercase. This includes Unicode characters from Asian languages.
Depending on the app/situation, the acceptable password characters will vary. For example, when entering an email password or an iTunes password, you can enter in any of the characters available to you within iOS. 

For a phone lock passcode, you must use a 4-digit numerical code to lock the phone. It does not accept other options. 

Various other programs, such as 1Password, also accept their own set of characters although this software applies to the first part, which is that it accepts whichever characters are available to you in iOS.