What does HGW stand for?

Haigwai - Language code (ETLW)

Hansestadt Greifswald - German license plate city code

Harris Gunworks - NCIC firearms make code (NCIC)

Heat-Generaring Waste (SAUS)

Heat-Generative Radioactive Wastes - Nuclear energy

High Tech Cats Inc., Kemah, TX - Manufacturer code for watercraft hull identification number (USCG)

Hyper-Quenched Glassy Water - Material science