While traversable's session history traversal queue's algorithm set contains one or more synchronous navigation steps with a target navigable not contained in navigablesThatMustWaitBeforeHandlingSyncNavigation:

1. Let steps be the first item in traversable's session history traversal queue's algorithm set that is synchronous navigation steps with a target navigable not contained in navigablesThatMustWaitBeforeHandlingSyncNavigation.

2. Remove steps from traversable's session history traversal queue's algorithm set.

3. Set traversable's running nested apply history step to true.

4. Run steps.

5. Set traversable's running nested apply history step to false.

Synchronous navigations that are intended to take place before this traversal jump the queue at this point, so they can be added to the correct place in traversable's session history entries before this traversal potentially unloads their document. More details can be found here.