• Few Requirement Management applications are offering configuration capabilities; most of them provide attribute filtering only. ENOVIA Requirements Central manages several kinds of effectivities and uses one configuration engine for all of the V6 applications. 
• Reqtify, the best in class requirements traceability tool (acquired by Dassault Systemes in 2010) is integrated with ENOVIA Requirements Central; this integration expands how requirement input can be captured in ENOVIA Requirement Central.
• ENOVIA Requirements Central users benefit from advanced spell-checking capabilities and an enhanced user interface

What is the link between those items?

They are all ENOVIA Requirements Central recent improvements. You will find detailed information in the attached pdf.