is a collaborative, community activity with a mission to create, maintain, and promote schemas for structured data on the Internet, on web pages, in email messages, and beyond.’

The schemas have varying support in search engines and devices, but might help search ranking and search result views.

Simen Brekken informed me on Slack that Google will ignore everything which they don’t natively support.

Using as starting points for data modelling

There are a lot of schemas defined by, and sometimes it can be useful to look to these if you are stuck in a particular problem space when trying to model your data.

Also, wouldn’t it be great if there was a tool that allowed you to attach arbitrary editable schemas to any document?

Testing schemas

It’s possible to test what they support using the Google Structured Data Testing Tool.

He also mentioned that there is ‘fine-print’ associated with each schema type that Google support and you might have to sign up for a beta-programme to benefit from some of the effects.

See Schema and data modelling.