The new MDN design moves a number of components into the sidebar. This page describes these elements and the thinking behind them.
When reviews are requested by contributors, we want to make that obvious, and make it easy for readers to mark off the reviews as complete. To do this, we want to add a "Reviews requested" box in the sidebar, like this:
The "Reviews" box only appears when there is at least one review requested for the page the user is looking at. Each type of review is listed, with a checkbox the user can mark if they've performed that review. Clicking the "Update" button saves their changes and refreshes the sidebar to remove any completed reviews from the list (and remove the box entirely if all reviews are complete).
Note: Obviously, the exact order of the boxes in the sidebar is up to discussion, and the UX team will be a lot of help here!
We're also considering a two-sidebar layout to let us better adapt to support quick-link lists on HTML and CSS pages, for example. A mockup of this layout is below.