Gets or sets the text value of a TimelineMarker.
When the TimelineMarker represents a Windows Media marker, this property contains the value of its "Name" field. When the TimelineMarker represents a script command, this property contains the value of its "Param" field.
The XAML syntax for TimelineMarker is mainly only relevant for a CreateFromXaml scenario. Populating the initial .Markers collection in XAML is permitted by the parser but has no effect because the .Markers collection is specific to a media source instead of a MediaElement. For more information, see TimelineMarker.