During the export in Outlook, before saving the ICS:
- In the dialog click “further options” (or so*)
- Choose “Show >>”* to show the “extended options”
- Activate the checkbox “Include details of elements marked private”*
- Save ICS
Now you have all details of the elements in the ICS file. If you then really need to “unprivate” the elements for further use, open the ICS file with any notepad and replace all occurences of “CLASS:PRIVATE” with “CLASS:PUBLIC”.
(*) I’m using Outlook in another language.