Can I add new Attendance codes to SIMS? Posted on October 31, 2012August 17, 2015 by Verity.Ridge You cannot add new codes to Attendance. These are strictly defined by the DfE. We do no not recommend editing Description, Statistical or Physical Meanings of any of the codes. Reviewed 17/08/2015 Posted in Attendance, SIMS.net and tagged Attendance, code, new.