Any topic can be an embedded topic, subject to these rules:
Changes in the embedded topic propagate to all of its container topics
Changes that you make to the content of the embedded topic are reflected in all container topics that include the embedded topic.
You cannot edit the embedded topic from within a container topic
When you are working in the container topic, Author-it rules prevent you from modifying the content of the embedded topic. The editing commands are disabled when your cursor is inside the embedded (gray) content. This is to ensure that the embedded topic is edited at its source. All users should carefully consider where the source embedded topic is being used (in container topics) before making changes to its content.
From the container topic, copy-paste of embedded content is limited
When you are working in the container topic, your copy-paste options with the embedded topic are limited to plain text strings only. For example:
To properly copy embedded content with its style formatting, you need to first open the embedded topic
To copy successfully from an embedded topic, first open the embedded topic and copy the content before pasting the content. More...
You can embed any number of topics within a container topic
A topic can contain any number of embedded topics, as well as ordinary paragraphs and objects.
To embed content from several topics into one topic, embed directly from the source, rather than nesting the topics
Where you want to embed content from several topics into another topic, the best practice is to simply embed the content from each source topic into the container topic rather than nest the topics (embedded within embedded within embedded...).
A topic cannot be embedded into itself, nor can it be embedded into any of its own children or their children.
An embedded topic can contain other embedded topics (as in nested tables). However, a topic cannot be embedded into itself.
If a topic is embedded into any descendant of itself, that instance will be ignored during publishing.