Public correspondence may however be kept if it is sufficiently significant that it should be retained for the historical record, or for other legitimate business reasons.
Fodd bynnag, gellir cadw gohebiaeth gyhoeddus os yw’n ddigon arwyddocaol fel y dylid ei chadw ar gyfer y cofnod hanesyddol, neu am resymau busnes cyfreithlon eraill.