PDF/A only. Gets or sets an optional string describing the relationship of the embedded file and the containing document. This string can be a predefined value or should follow the rules for second-class names (ISO 32000-1, Annex E). Predefined values are "Source", "Data", "Alternative", "Supplement" or "Unspecified". It is null, if a relationship string is not available.


public string Relationship { get; set; }
Public Property Relationship() As String