When making type catalogs in Revit using a spreadsheet editor (through XLS or CSV) format), you convert your table to a comma-separated text file in .txt format. When using special characters in your type catalog like i.e. “é” or “à” or “â” (mainly in French language) you’ll need to check the encoding of your text file. The encoding should be set to “Unicode” at least. “UTC-8” won’t work in Revit and will give you scrambled characters like “@&” in the catalog table dialog when loading the family.
The encoding can be changed by easy applications like Windows Notepad or Notepad ++.