What does QSD stand for?

What does QSD mean?

QSD	Quitman School District Community » Educational
QSD	Is my keying defective? Academic & Science » Amateur Radio
QSD	Quality System Designs Business » Firms
QSD	Quincy School District Community » Educational
QSD	Quality Systems Development Business » Firms
QSD	Quality Software Development Business » General
QSD	Quality System Design Business » General
QSD	Quality System Design Governmental » Military
QSD	Quality System Design Governmental » NASA
QSD	Quantized Spatial Decomposition Miscellaneous » Unclassified
QSD	Quit Smoking Diary Medical