We have several Macs sharing an iCloud account so that we can share the Calender. But I need to stop sharing the clipboard. Sometimes a user tries to paste something from their clipboard, but what pastes comes from another Mac's clipboard. How can I stop sharing the clipboard, but keep the shared Calendar and shared files?
MacBook Air 13″, macOS 10.15
The clipboard will be shared, when you are using the same Apple ID.
It would be much more convenient to have separate Apple IDs, and then use Family Sharing (Family Sharing - Apple Support) to share your purchases and your subscriptions and the Cloud storage. You can create shared family calendar andante a shared family album for your photos.
See an article Use Universal Clipboard to copy and paste between your Apple devices - Apple Support
You have to sign out Apple ID from the devices and keep Mac signed in , the iCloud photo sharing , calendars will also stop .
However only photos can be shared using albums with different apple id and password signed in devices .
Calendars are synchronized via that single Apple ID and Password all are using. You can deselect Calendar in System Preferences > Apple ID > iCloud
Best practice calls for each individual to have their own separate and distinct Apple ID. If for no other reasons, privacy and accountability. But, that's a personal choice in the end.
Each specific calendar (Work, Home, Personal ....) can be shared individually. Whether to not this does what you want is unknown .
How to STOP sharing a clipboard between Macs sharing an iCloud account
