What does WSF stand for?

According to the Related Link, WAFS stands for: {| ! ! | Welding of Airframes by Friction Stir Wide Area File System (storage technology) Wide-Area File Services (storage technology) Wilkes Acoustic/Folk Society Inc. (North Wilkesboro, NC Women's Auxiliary Flying Squadron World Area Forecast Satellite Broadcast System World Aviation Forecast System Write-Ahead File System |}