google-search

<entry-title>Google Search</entry-title>

Google is one of several search-engines that index and support microformats.

main search

Google.com supports rel-nofollow, hCard, hReview, hReview aggregate, hProduct (since 2009-05-12 for rich snippets), hCalendar (since 2010-01-22), and hRecipe (since 2010-04-13) - in main search. See also related blog post on hCalendar hRecipe support.

rich snippets

Main article: rich-snippets

Rich Snippets is Google's term for the enhancement of search results ("snippets") with information from microformats from pages.

• See google-rich-snippets-examples for documentation of Google's microformats examples.
• See google-rich-snippets-issues for issues with Google's Rich Snippets Testing tool.

reviews

Google's documentation on Rich snippets - Reviews support describes details:

• the main topic of the page needs to be about a specific product or service. For example, using review markup on a page containing multiple products is not supported.
• If the markup contains a single review, the reviewer’s name needs to be a valid name (Person or Organization)
  • presumably an hCard

hReview properties supported (bold = required)

• item
  • fn
• rating
  • value
  • best
    • value-title support:

       <span class="best"><span class="value-title" title="10"/></span>
      

  • worst
  • "Tip: Don't add a separate hidden text block to specify the rating. Hidden content will not be displayed."[1]
  • img alt number parsing:

    <img class="rating" src="four_star_rating.gif" alt="4 Star Rating: Recommended" />
    

  • value-title support:

    <span class="rating"><span class="value-title" title="4.5" /></span>
    

• reviewer
• dtreviewed
• description
• summary

hReview-aggregate additional properties supported in addition to the above (or additional requirements / subproperties)

• count - "The total number of reviews for the item on your site. Note: Whenever you include count, the page must also contain review markup for each reviewed item. count should only include reviews on your own site."
• votes - "contributes toward the average rating but not towards the number of reviews available" - essentially, a "number of ratings" property.
• rating - required in their hReview-aggregate support
• rating
  • average (additional subproperty)
• photo - though presumably this works in hReviews as well

advanced search

Through additional user interfaces:

• Google Advanced Search - Usage rights supports rel-license (since 2005(?) citation needed)

search APIs

Google provides search APIs like:

• Google Social Graph API supports XFN (launched 2008 February). See "Google Social Graph API How are your sites connected?".

see also

• search-engines
• implementations