SHA stands for Shanghai Hongqiao Intl Airport. Codes like this one are often called IATA codes, a set of identifiers established by IATA (International Air Transport Association) that is widely used by airlines and the aviation industry. Shanghai Pu Dong Airport (PVG), Hangzhou Airport (HGH), Wuxi Airport (WUX), Nantong Airport (NTG), Suzhou Airport (SZV) are some additional IATA codes for airports related to your trip.