Latest PageRank News
PageRank is an algorithm developed by Google to rank websites in the Search Engine Result Pages (SERPs) based upon the number and quality of the backlinks of a page.
Buying backlinks is against the Google Webmaster Guidelines. As such, you should use rel=nofollow or rel=sponsored SEO Signals, such as PageRank from being passed.
Using internal Nofollow links for PageRank Sculpting is a waste of time and does not work.
Google's Gary Illyes has said that there is no need to update external backlinks when migrating to HTTPS. The link juice loss is minimal.