Incorporating a massive number of rel attributes into HTML5 was essential for the direction that web design has taken. The benefit of this expanding library is to let the crawlers efficiently interpret vital information about the content they are looking at. Is it a section? Is it a help document? Is it a table of contents? Expanded rel attributes allow the document to tell the crawler exactly what it is looking at. Thus, improved indexing and display on relevant SERPs is expected.
Some of the attributes that are to be made standard in HTML5 include the previously non-standard but Video Production Service widely used “rel-nofollow” and “rel-pingback”, developed and used by Google and WordPress, respectively.
