Noindex: Tells a search engine not to index a page.

    Index: Tells a search engine to index a page. Note that you don’t need to add this meta tag; it’s the default.

    Follow: Even if the page isn’t indexed, the crawler should follow all the links on a page and pass equity to the linked pages.

    Nofollow: Tells a crawler not to follow any links on a page or pass along any link equity.

    Noimageindex: Tells a crawler not to index any images on a page.

    None: Equivalent to using both the noindex and nofollow tags simultaneously.

    Noarchive: Search engines should not show a cached link to this page on a SERP.

    Nocache: Same as noarchive, but only used by Internet Explorer and Firefox.

    Nosnippet: Tells a search engine not to show a snippet of this page (i.e. meta description) of this page on a SERP.

    Noodyp/noydir [OBSOLETE]: Prevents search engines from using a page’s DMOZ description as the SERP snippet for this page. However, DMOZ was retired in early 2017, making this tag obsolete.

    Unavailable_after: Search engines should no longer index this page after a particular date.