Labelling web content with RDFa for Rich Snippets
Above all else, structured data exists to help facilitate web searches. Site owners who semantically tag information on their homepage enable search engines to extract this data and display it with the help of features like Rich Snippets. These contain excerpts of web content that are displayed in the search engine result lists (SERPs), allowing them to stand out more. To this effect, semantic annotation contributes to a website’s search engine optimization. The market leader, Google, supports RDFa markup for Rich Snippets for data types like recipes, user reviews, software, and news articles. Rich Snippets for videos are only supported in more current formats, like Microdata and JSON-LD. And for events, Rich Snippets need to be tagged with JSON-LD. Below is an example on how web content can edited for Rich Snippets:
Tagging product reviews with RDFa
Product reviews that appear in the SERPS as Rich Snippets generally contain product names, an image of the product, a rating (usually in a 1-5 star format), and user reviews (which include the author’s name, titles and dates). The following code shows how this information is tagged for machine readability using RDFa: