Are Blu-ray and HD-DVD Discs Region Coded, Like DVDs?

For Blu-ray Discs, there are three regions, designated as follows:

Region A: U.S., Japan, Latin America, East Asia (except China).

Region B: Europe, Africa, Australia, New Zealand

Region C: China, Russia, Remaining countries.

HD-DVD had indicated the possibility of, but never announced a specific Region Coding for its format. As a result, HD-DVD disc titles were never region coded.