Extending getFeatureInfo with (custom) metadata of a GeoServer WMS endpoint

GeoServer GeoServer User
1

I am trying to add metadata to a getFeatureInfo request return of a GeoServer instance (any recent version… 2.24.4 or later using the Kartoza docker). I added a content.ftl to the configuration and this works as expected:

<caption class="featureInfo">${type.name}</caption><br />
<caption class="featureInfo">${type.namespace}</caption>

But this does not:

<caption class="featureInfo">${type.abstract}</caption><br />

Is there a way to add other metadata fields to the html getFeatureInfo request return?

What other metadata fields are available?

Is it possible to add custom metadata fields using the metadata plugin (Metadata — GeoServer 2.27.x User Manual)?
How can these custom fields be accessed?