Your machine or some part of it may not function properly if you name a file or folder incorrectly.

Use the list of rules below to see if you have made these errors and may want to correct them.

Folder names

• Folder names shouldn't be longer than 100 characters including spaces.
• You cannot use the following characters anywhere in a folder name or a server name: 
  • Tilde (~)
  • Number sign (#)
  • Percent (%)
  • Ampersand (&)
  • Asterisk (*)
  • Braces ({ })
  • Backslash (\)
  • Colon (:)
  • Angle brackets (< >)
  • Question mark (?)
  • Slash (/)
  • Pipe (|)
  • Quotation mark (")
• You cannot use the period character consecutively in the middle of a folder name.
• You cannot use the period character at the end of a folder name.
• You cannot start a folder name with a period character.
• If you use an underscore character (_) at the beginning of a folder name, the folder will be a hidden folder.
• Additionally, a folder that contains the string "_vti_" is reserved by SharePoint, and isn’t supported.

File names

• File names shouldn't be longer than 100 characters including spaces.
• File paths shouldn't be longer than 255 characters including spaces.
• You cannot use the following characters anywhere in a file name: 
  • Tilde (~)
  • Number sign (#)
  • Percent (%)
  • Ampersand (&)
  • Asterisk (*)
  • Braces ({ })
  • Backslash (\)
  • Colon (:)
  • Angle brackets (< >)
  • Question mark (?)
  • Slash (/)
  • Pipe (|)
  • Quotation mark (")
• You cannot use the period character consecutively in the middle of a file name.
• You cannot use the period character at the end of a file name.
• You cannot start a file name by using the period character.
• If you use an underscore character (_) at the beginning of a file name, the file will be a hidden file.
• file names and folder names may not end with any of the following strings: 
  • .files
  • _files
  • -Dateien
  • _fichiers
  • _bestanden
  • _file
  • _archivos
  • -filer
  • _tiedostot
  • _pliki
  • _soubory
  • _elemei
  • _ficheiros
  • _arquivos
  • _dosyalar
  • _datoteke
  • _fitxers
  • _failid
  • _fails
  • _bylos
  • _fajlovi
  • _fitxategiak
• In addition, file names and folder names cannot start with the “_vti_” string, such as the followings:
  • _vti_cnf
  • _vti_pvt
  • _vti_bin
  • _vti_txt