Background
Several Wikipedia articles (approximately 3 million on English Wikipedia alone) use a CSS class called vevent to display events. Examples of articles that have such an element are:
https://en.wikipedia.org/wiki/2007_Steelback_Grand_Prix
https://en.wikipedia.org/wiki/File:Mes-e6.svg
https://en.wikipedia.org/wiki/File:Bulgaria-Army-OR-5.svg
https://en.wikipedia.org/wiki/List_of_Riverdale_episodes
The hCalendar microdata format allows marking up events with the vevent CSS class. There is a minimum set of expected fields that are supposed to accompany a vevent element.
vevent is intended to allow marking up events in the sense of events that people can attend, such as concerts, shows, and such. Search engines (Google at the very least) use this to render events in a rich result format. However, given that most Wikipedia articles seem to use vevent for past / historical events and that several required fields such as location and dstart aren't provided, Google's Search Console reports millions of errors for incomplete events.
This is not a problem in any sense that it affects users directly. As far as Google's public documentation is concerned, there isn't any declared impact on search ranking. This task can be closed if we can conclude with one of the following:
- The use of vevent in this way is unintentional. It might be good to remove it (as a very, very low-priority task)
- The use if vevent in this way is intentional and capture the intention in this task.
- The use of vevent in this way is intentional but it is not complete, and refer to the task that would make it complete.