The LegacyYesNoProperty represents a Boolean value. For historical reasons, this type is used instead of BooleanProperty (section 184.108.40.206) for certain properties. This type is equivalent to YesNoProperty, but null values are permitted and have the same meaning as "N" (false).
Simple type: eDT_LPWSTR.
Validity: If not null, MUST be one of the following values: "Y" (for true) or "N" (for false).
Server validation: Servers MUST enforce validity constraints.
Client validation: Clients MUST enforce validity constraints.