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
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>
- value-title support:
- 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?".