In the prehistoric ages of Krypton, Rao was the name of an ancient sun-god, part of a larger Kryptonian pantheon.
But when the people of Krypton later came to worship just one God, the name Rao was applied to Him.
In that earlier, unrecorded mythology of old, Rao as the sun-god was deemed to be the chief of all gods.
At that time, so great was the respect for the red sun of Krypton that any soldier of Erok's time automatically
became an officer if he had red hair.
When Jaf-El later preached the worship of the One God, he gave Him the name of Rao, though no longer identifying Him specifically with the sun:
Note that in later wedding ceremonies, the phrase used was "Rao, who kindled the sun," not "Rao, the sun" —
showing Rao to now be the sun's creator; no longer the sun itself —