Loading the question bank
Revision question · Vehicle handling
Revision material from the imported DVSA bank includes source-checked Lanekind learning corrections. These corrections are not newly issued official examination questions, and practice does not reproduce a live test paper.

The purpose of a box junction is to keep the junction clear by preventing vehicles from stopping in the path of crossing traffic.
You mustn't enter a box junction unless your exit is clear. However, you may enter the box and wait if you want to turn right and are only prevented from doing so by oncoming traffic.
Reviewed reading for this question