The South Korean and US Armies have established a command system on Korea''s border islands in the Yellow Sea that is interoperable with the Combined Enterprise Regional Information Exchange System–Korea, or CENTRIXS-K. A South Korean military official said equipment for the CENTRIXS-K has been installed at Marine Corps units on Yeonpyeong and Baengnyeong Islands, according to Korean (KBS WORLD) website. The official said the system has been operating since September 26th through which any military situation occurring on the northwestern islands is being verified on a real time basis. CENTRIXS-K is a key South Korea-US joint command and control system on the Korean Peninsula that enables prompt notice of field situations to the top commander. The system is in operation at 20 locations in South Korea including the Combined Forces Command headquarters on Yongsan Garrison.