Provide at least one content focus for each viewport (including frames) where enabled elements are part of the rendered content.
Allow the user to make the content focus of each viewport the current focus.
Normative inclusions and exclusions
When a viewport includes no enabled elements (either because the format does not provide for this, or a given piece of content has no enabled elements), the content focus requirements of the following checkpoints do not apply: 1.2, 5.1, 5.4, 6.6, 7.1, 9.3, 9.4, 9.5, 9.6, 9.7, 10.2, and 11.5.