What does HSK stand for?

What does HSK mean?

HSK	Hanyu Shuiping Kaoshi Community » Educational
HSK	Hanyu Shuiping Kaoshi Academic & Science » Universities
HSK	Husk Miscellaneous » Food
HSK	Hohl Shaft Kegel Business » Firms
HSK	Hard Style Killers (stamps) Miscellaneous » Hobbies
HSK	Hollow Short Kegel Medical » Physiology
HSK	Heavy Secret Killers Governmental » Police
HSK	Hesh Skate Krew Governmental » Police
HSK	Horizontal Sling Kit Governmental » NASA
HSK	Heemskirk Consolidated Ltd Business » ASX Symbols