Buggies are to be left in the shelter in the playground, and not brought into the school.
Presumably parents are meant to take their younger child or children out of the buggy and carry or walk them into the school.
Really impracticable, if you ask me. For example, DS3 is 2.7 so he can walk, but he will not get out of the buggy in situations where he feels uncomfortable, or doesn't know where he is. What is DH supposed to do, leave him out in the playground in the dark?