You may have seen a notice on a light sold on the Sunco website that states you cannot buy certain light bulbs in California. The California Energy Commission (CEC) established certain appliance efficiency regulations with Title 20 and building standards with Title 24. Those regulations can limit the sale within California of certain products.
Title 20 affects electrical products of all types, including lamps/bulbs, portable lighting fixtures, torchieres and lighting controls, among other things.
Title 24 pertains to building regulations that would be enforced by local building inspectors. That affects permanently wired fixtures.