Mandatory red-star indicator isn't needed when the user cannot change a property value.
For example if the following is used:
@DomainObject(objectType = "XXX", nature = Nature.VIEW_MODEL, editing = Editing.DISABLED)
It seems a View Model will by default have all mandatory properties ( @Column(allowsNull="false")?), so the class level attribute 'editing = Editing.DISABLED' is useful to suppress that.