OPT

• Channel One Russia
• Eliyahu M. Goldratt
• Filesystem Hierarchy Standard
• Filling station
• ORT (disambiguation)
• Ocean Power Technologies
• Operation Prime Time
• Opt in email
• Opt-out
• Optical projection tomography
• Opting out
• Option key
• Optional Practical Training
• Oral pressure therapy
• Overseas Passenger Terminal
• Oxford Placement Test
• Palestine