MacOS X uses UTF-8 Normalization Form D (NFD) whereas Microsoft Windows and most other applications use UTF-8 Normalization Form C (NFC). The difference is that in NFD Unicode character sequences containing diacritical marks are decomposed whereas in NFC the Unicode character sequences use combined characters whenever possible. Whereas Microsoft Windows can display and manipulate files stored using NFD, MacOS X Finder does have trouble with filenames that are NFC encoded. All file names stored by the OpenAFS Windows client use NFC.