When subjects and classes are initially created, a default Attendance code is set to determine what code students marked 'Present' in the class sessions will receive.
Generally once this is set it does not change however there are circumstances where there may be a change to the default attendance code mid year (i.e. the school is required to close and deliver classes via remote learning and a difference code for attendance in that circumstance is required).
The Bulk Attendance code updating tool allows you to bulk update selected subject/classes to have a difference default attendance code for future sessions. This change will not impact the attendance code data recorded for past sessions.
For schools using third-party timetable software, all the import jobs from the external timetable will check the current default Attendance Status set for a subject to populate future class sessions being generated.