To retain all the special characters in the data dictionary:
When you download the file from REDCap, it comes out encoded as UTF-8, which is correct if you want the special characters to display correctly. As soon as you open it in Excel and save it, Excel automatically changes the encoding back to ANSI. When you upload that dictionary back into REDCap you see jumbled characters.
Downloading this addin to Excel:
Click the “Unicode CSV” tab and click Save, instead of saving it regularly.
Alternatively, you can save the file in Excel and then open it in Notepad or Notepad++, then click save as and change the encoding to UTF-8.