When mask is parsed the result is a collection of SectionBase derived objects. This property returns that collection. Each SectionBase object has a collection of its display characters return via its SectionBase.DisplayChars property. XamMaskedInput also exposes a collection that contains aggregate display characters of all sections via its XamMaskedInput.DisplayChars property.

This property is useful for example if you want to query and find out the structure of the parsed mask or to query and/or manipulate the current user input on a per section or per display character basis.

Reference