What is date gold hallmark with letter h?

A gold hallmark with the letter "H" typically indicates that the item was assayed in Hong Kong, which is one of the hallmarking authorities for precious metals. Hallmarks provide information about the metal's purity and the location where it was tested. In Hong Kong, a common hallmark for gold is "375," "585," or "750," indicating different levels of gold purity. Always check for additional symbols or numbers to confirm the specifics of your gold piece.