Generally, if shortage of work is why you are laying them off, i.e. you have closed your retail business or have reduced operations, use code A (Shortage of Work). If the person is sick or in mandated quarantine, use code D (Illness or Injury). If the employee refuses to come to work but is not sick or quarantined, use code E (Quit) or code N (Leave of absence), as appropriate. To expedite processing, do not add comments.
For more Q&As specifically on ROE coding and other payroll questions arising from COVID-19, see COVID-19 Canadian Payroll Association guidance.