Clean a calendar invite before sharing CALSCRUB

What is in a meeting invitation

An .ics file is plain text, and forwarding one forwards all of it. The parts people do not expect:

• Every attendee's email address, in an ATTENDEE line each, along with their response status. A forwarded invitation for a thirty-person meeting is a thirty-address distribution list, and who accepted.
• The dial-in details and the PIN, usually in the description, frequently a permanent meeting room and PIN rather than a one-off. Those are a credential.
• The join link, which for several platforms embeds a token that admits the holder.
• The organiser's address and their scheduling software, in ORGANIZER and PRODID, which names the product and often the version an organisation runs.
• The recurrence rule and the history of exceptions, which describes a pattern of movement.
• The description in full, including the agenda notes somebody typed for internal readers.

The two ways an invitation leaks

Forwarding one to bring somebody in, which hands them the attendee list and the PIN along with the time. And exporting a calendar to move it between accounts, which produces a single file containing every meeting you have had, then attaching that to a support ticket.

The second is the one that does real damage, because a year of invitations is a map of who an organisation talks to, when the board meets, which clients exist and which deals were live in which weeks.

What it leaves

The time, the title and the structure, so the file still works as an invitation. What you remove is your choice rather than a fixed list, because there is no single right answer: sending a colleague a meeting without the dial-in is useless, and sending a supplier one with the whole attendee list is careless.

It reads and rewrites the file in this tab. For the wider question of what a document carries when you pass it on, SCRUB handles Office files and X-RAY will list what is in almost anything.