High Swirl Combustion Hardware Systems Command Health Services Command Hierarchical Storage Controller High Speed Channel Homeland Security Council Human Systems Center Hardware/Software Coordination Health and Safety Code Health and Safety Commission Headquarters and Supply Company Health Sciences Center High Speed Connector High-Speed Craft Hardware and Software Coordination Hardware System Command Health Service Commissioner hematopoietic stem cell hematopoietic stem cells hepatic stellate cells Herschel Science Centre Hexadecimal Sequential Code High Speed Connect Higher School Certificate Hospital for Sick Children Host System Component hysteroscopy haematopoietic stem cell haematopoietic stem cells haemopoietic stem cell haemopoietic stem cells Hall Social Coordinator Hampden-Sydney College Hand and shoe contamination Hardman System Command Hardware Systems Commands Harmonised System Code Harmonized System Committee HARSCO CORP. Harsco Corporation