Rec. 2020 (current) World Network of Biosphere Reserves in Europe and North America History of the web browser U.S. Postal Service Complex geometry MacMahon's master theorem Open Design Alliance Radium and radon in the environment Style guide Zebra patterning Open back rounded vowel Federative International Programme on Anatomical Terminology Split-flap display Current sensing Doctor of Humane Letters Authentication (law) Analog circuit Amazon Elastic Compute Cloud Call-progress tone Armed Forces of Ukraine Vestibule (architecture) Forwarding information base Spectrum analyzer