An event list tells an adversary who belongs together, who has access and which relationships the institution does not advertise.
Where this breaks
The danger appears when planners, venues, security, caterers and guests receive different copies with permanent access.
The operating move
Limit every recipient to the slice required for their task. Use coded operational lists where names add no value.
Value object — The operational card
- Invitees, roles and sensitive relationships
- Recipients and copies
- Expiry and deletion
- Incident owner
The test
Ask each provider to return its list. The copies nobody can locate are the real exposure.