The exceptional circumstances code (Y) can be applied to the whole school, e.g. if the school has been closed for a snow or heating related issue, or it can be applied just to certain year and registration groups

It is a statutory requirement that a reason is recorded for each exceptional circumstance

Focus > Attendance OR Lesson Monitor > Exceptional Circumstances

Choose the date range and the group type you wish the Y code to be applied to, then choose the Y code on the dropdown option. 

You will need to enter a description for the reason it's being applied e.g. "Whole School Snow Day closure 01/12/18"