This documentation is not using the current rendering mechanism and is probably outdated. The extension maintainer should switch to the new system. Details on how to use the rendering mechanism can be found here.
Rendering new database fields¶
If you want to render additional fields that are already available in the database (e.g., because you added them with your own extension), all you need to do is to add a marker in to the corresponding model file. If you provide a distinct database field named “agenda” and want to show it in the event detail view, simply put a marker “###AGENDA###” wherever you want to see it and you are done.