The best way to know the invalid characters is by understanding the invalid characters in SharePoint
(There can be some different rules for the different SharePoint versions)

Invalid characters – are related to SharePoint

The article (link) below lists the invalid characters in the different situations:

  • In Site names
  • In Folder names
  • In Server names
  • In File names
  • SharePoint invalid Characters
    https://support.microsoft.com/en-us/kb/905231
  • Dash (-) in the file names
    http://sharepoint.stackexchange.com/questions/121022/sharepoint-2013-search-does-not-find-specific-document

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