"Mark as Private" checkbox is an important feature in Notes Client Mail. The same feature is also available in IBM Verse and SCN web as well.
The behavior of this checkbox is however different in one scenario when used from Notes Client Mail as compared to its usage from IBM Verse or SCN Web.
Notes Client Mail -->
We can create a meeting from Notes client Mail and can saved it without checking the checkbox "Mark as private".
The checkbox "Mark as private" can be checked later on once meeting is created.
SCN Web/IBM Verse -->
"Mark as private" setting cannot be done later in IBM Verse and SCNotes. It needs to be done while creating a Meeting.
If meeting is open, then this checkbox "Mark as private" is disabled(grayish). It doesn't allow to be changed.