Let's look at the rendering algorithm.

Step 3.2.1 says ordered node list is an empty list (that will have stuff).

Step 3.2.8 says that ordered node list is an empty list. This is rundandant.

Step 3.2.9 mentions "unmarked" elements. This isn't really defined and only becomes clear when you read substeps of 3.2.9 about visiting and marking a node. Not sure what to do here, if anything.