Support for foreign content vocabulary (<unknown> element)

DITA 1.1 introduces the <unknown> element to incorporate existing standard vocabularies for special content, like MathML and SVG, as inline objects.

Note: Because OASIS DITA 1.1 was not yet approved at the time DITA Open Toolkit 1.3 was released, the functionality described here should be considered preliminary until DITA 1.1 is approved, the 1.3 Toolkit assessed relative to DITA 1.1, and appropriate changes made to the Toolkit, if necessary.

As a DITA content author you can add the <unknown> element, and put content inside it. When you transform the DITA files to the output you want, the transformation ignores the <data> element and any content inside it.

If you specialize the <data> element, and put information inside the specialized element, you can create a transform override that allows the information to appear correctly in the output.