Schema.org

Schema.org (aka Schema) is a collaborative effort initiated by Google, Microsoft and Yahoo! to develop and support a vocabulary of tags webmasters can add to their webpages (or html-formatted emails) to improve the way search engines (and email services) read and display content.

Improvements can be seen in the snippets describing the webpages in the search result pages (SERP). For the pages that use Schema, the so-called rich snippets provide additional information that help users gauge the relevance of the website.

For example, a property search listing may show floor area, selling price, and other relevant facets about the property. Similarly, the search result for a cake recipe may show the average preparation time, in addition to rating and votes, as can be seen in Exhibit 26.11.

JSON-LD, microdata and RDFa are the most frequently used ways to mark up a webpage with Schema vocabulary. Though all three standards are widely supported, preference has varied over the years. Google currently recommends JSON-LD for all data types except breadcrumbs. This is probably because the format makes it easier to markup structured data, especially if it is generated programmatically from tools that support JSON. Whereas microdata and RDFa embed the tags in the HTML of the webpages, JSON-LD forms a block of code in the webpage separate from the presentation layer. (Google recommends adding the code to the head section).

Exhibit 26.12 depicts how information about a movie and its director is marked up using microdata. The attribute itemtype along with the schema URL mark the data as “movie”, and attribute itemscope defines the scope. The itemprop attribute is used to label properties. In this example, name, director and genre are the properties of the item, and name, birth date and death date are the properties of the property director.

Exhibit 26.13 depicts how the same information is marked up using JSON-LD.

The required code may be generated using Google’s Structured Data Markup Helper (Exhibit 26.14).