All the above tags are not necessary since search engines are set to index pages by default, Above tag tell search engine crawlers not to index that particular page, ROBOTS : NOINDEX, NOFOLLOW Above tag tell the search engines not to index that particular page and also not to follow any links from that page, usually if you want to exclude crawler from that particular page completely, Above tag tells the crawlers to index this page but not to follow the links from this particular page, Above tag tells the robots not to index and rank this particular page but they can follow links from this particular page and find other pages of the site or external site pages linked from this page. Tells the robots not to make a cache copy of this particular page, Good for saving bandwidth used up by crawlers, Tells googlebot google's crawler not to take a cache of this page, Tells googlebot not to index this particular page Another useful tag to prevent crawling from indexing pages, hope this helps SEO BLog team,