They are the reasons staff must choose when removing retail stock (e.g. Waste, Sample, Staff meal, Damaged). Go to Settings > Kitchen Settings > Stock Management Justifications (/admin/movementsreasons), click Add new, enter a Description (required) and keep Is Active? ticked, then Save. The list has Active and Inactive tabs. In the current version the Stock Movement pop-up lists all justifications, including inactive ones, so rename or keep them tidy rather than relying on the Is Active? setting. The menu entry appears with the Retail or Wholesale module and needs the List/Edit Stock Management Justification permissions.