What does DDO stand for?

What does DDO mean?

DDO	Disk Drive Overlay Computing » Software
DDO	Doubled Die Obverse Miscellaneous » Coins
DDO	Designated Detention Officer Governmental » Police
DDO	Digital Dental Office Miscellaneous » Funnies
DDO	Device Driver Overlay Computing » Software
DDO	Dynamic Decision Ordering Business » Products
DDO	Dominion Drop Out Community » Sports
DDO	Discrete Digital Output Governmental » NASA
DDO	Deputy Director of Operations Governmental » Military
DDO	Dungeons and Dragons Online Internet
DDO	Data Dictionary Object Computing » Databases