If someone logs in at a high security level, they are also given access at all lower security levels. (i.e. If a person logs in with the Edit UserID and Password, then they will get Edit access, as well as the lower access levels: Add and View)
If you want a single UserID and Password for all types of editing (add, edit, and delete), then check both: Adding and Editing, and give both the same User ID and Password
*** If you log in using your iCal Registration Name and Registration Number, you will get 'Super-User' privileges, and will get Settings-level access to any calendar on your machine (useful if you forget your calendar's password)***
Example Security Settings: |