Many templates serve merely as wrapper around free-form wikitext content. TemplateData specifies the parameter type "content" for this purpose.
This task tracks the implementation in VisualEditor to provide an edit surface for editing the values of these parameter. Similar to how we already support rich editing of the content inside References.
* Wrap-templates. Such as message boxes, and the parameter-consuming variants of the "something-start"/"something-end" templates.
* Nested infoboxes.
* Simple infobox fields that support text but allow/encourage use of inline templates for formatting. Currently these expose raw wikitext to end-users.
>>! @Ironholds wrote
> A lot of infoboxes et al - the one on https://en.wikipedia.org/wiki/Fulgencio_(Modern_Family) comes to mind - have infoboxes /within/ the infoboxes that need editing. I'm not sure what the answer is here - it feels wrong, somehow, to offer an infinitely deep template inspector inside a template inspector inside...etc, but I can't think of another solution short of manually going around making the template namespace make sense or accepting that users will always have to learn markup, just not immediately.