Shared Calendars - Is Anybody Allowed to Put Something on Your Calendar?

I have a shared calendar with my wife, which is for various social events. I'm aware of when she will be out of the house or when we are doing something togetherwith other people. The Hello Internet calendar obviously is shared between myself and Brady,. There's a cortex calendar, which is shared between you and myself., also used for planning the recording. But on all of those shared calendars, I also have my personal assistant shared across those things.