The flight info example is one of the places where semantic web tech went mainstream. Those flight emails have embedded metadata in JSON-LD (linked data) format

The flight info example is one of the places where semantic web tech went mainstream. Those flight emails have embedded metadata in JSON-LD (linked data) format and Gmail uses it for more specialized display[1]. [1]: https://developers.google.com/gmail/markup/reference/flight-reservation https://developers.google.com/gmail/markup/reference/flight-...