Link sculpting is (or used to be) a way to control the flow of pr of a website. If you had 2 links on a site, link 'a' and 'b', but you wanted all the linkjuice to flow out of link 'a', you would tag link b 'n0f0ll0w', like plugging a hole in a swimming pool w/ 2 holes - it would flow stronger through the other hole. Now, even if you tag link b 'n0f0ll0w', it will still only flow out of link 'a' at 50% regardless.