Some Zot applications/implementations are able to support complex content structures including embedded apps, identity-aware content, and authenticated links. Not all implementations are required to support, or may be able to support these types of content. Additionally, the data serialisation formats supported by the implementation may affect the ability to fully represent rich identity-aware content.
An implementation which only supports ActivityStreams2 will receive "message" content as type 'Article', and which contains a generic HTML rendering of the source content in the "content" or "contentMap" elements. This generic rendering is suitable for any observer and some HTML links may be inaccessible due to permission and authentication requirements.
The source for the rendered HTML is available in the "source" element. Implementations which wish to support identity-aware content and authenticated links should use this source content (especially if it is type "text/x-zot-bbcode") to dynamically generate an HTML rendering that is specific to the current observer.
The exact feature set supported by the implementation and local security filtering MAY result in rendered content that is empty. Implementations MAY choose not to display rendered content that is empty or MAY indicate to the observer that the content could not be rendered sucessfully. Implementations SHOULD provide a menu option to 'view source' and provide the ability to access the original content if the rendering results in empty content and is a mimetype that is determined to be safe to display in source format.
The same considerations apply to content which uses the 'zot' serialisation. In this case, the content source is the "body" element and is of type "mimetype". The observer-neutral HTML rendering will be provided in the "html" element.