Team working: i need a PRIVATE flag in tasks to avoid to share my personal tasks in a shared workspace

In a business environment my calendar is shared between all team members.

In that situation i don't want to share my personal task details.

It's important to show in the calendar my busy time, but also is important to hide their details to anyone except me.

A simple solution (also found in other softwares) is the possibility to flag a task as PRIVATE

In that way a private task is showed in the shared calendar as busy time but without all details that remains hidden to other team members.