https://www.elevenplusexams.co.uk/appeals/general#a27Quote:
A27. Giving reasons for preferences on the CAF
There is a space on the CAF (Common Application Form) where parents are invited to give reasons. The space is there because it is a requirement that parents be offered an opportunity to state their reasons for wanting a particular school.
Quite often parents do not bother to fill in this part of the form, which is not a problem in so far as all the admission authority can normally do, anyway, is to allocate places strictly in accordance with the published criteria.
However, if there are good reasons for a preference, it is in my view worth stating them because, in the event of an appeal, there is a possibility that a copy of the CAF might be included in the case papers. Parents who suddenly have lots of “compelling reasons” for wanting a school place at appeal might be asked why those reasons were not quite so compelling as to merit a mention when they submitted their application.