The concept ConstrainedDelaunayTriangulationTraits_2 defines the requirements for the geometric traits class of a constrained Delaunay triangulation that supports intersections of input constraints. This is the case when the template parameter Itag of ( Constrained_Delaunay_triangulation_2<Traits,Tds,Itag>) is instantiated by one of the tag classes Exact_intersections_tag or Exact_predicates_tag). The concept ConstrainedDelaunayTriangulationTraits_2 refines both the concept DelaunayTriangulationTraits_2 and the concept ConstrainedTriangulationTraits_2.