Page Rank Sculpting deals with the rule of link flow structural design utilizing rel=”no follow” attribute and by organizing non-priority pages for SERP’s in an external include file, blocked with your robots.txt to stop your site link sap to pass for insignificant pages, entrusted sites and bad neighborhood

These can be put into practice to your least significant pages like sign up, cart page and so

This would work better for sites having hundreds and thousands of Web Pages that are not significant for keyword listing and in addition link sap loop to the domain