Mild Hayfever is Hayfever without Wheeze as stated.Can you define 'Mild Hay Fever'?
I would suggest that any form of hayfever requiring medication WASN'T mild. Thus, any medical record / prescriptions for hayfever are likely to see you ineligible. That, however, would be for the OASC Med staff to decide when you applied.
You dont have to have serious hayfever to take tablets for it, pretty much everybody who has hayfever takes tablets, mild or not.