YOS

AcronymDefinition
YOSYosemite (Amtrak station code; Yosemite, CA)
YOSYears Of Service
YOSOil Storage Barge (Non Self-Propelled)
YOSYour Operating System
YOSYour Obedient Servant (closing salutation chiefly 18th century British)
YOSYahoo Online Status (Yahoo Messenger)
YOSDistrict Barge, Oil Storage (US Navy)
YOSYttrium Ortho-Silicate