Invalid characters

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