The antiques world has plenty of trade slang — for example, dǎyǎn means "to misjudge and buy a fake".
Tips
mistakes
Pronounced háng (trade/profession), not xíng. The 行 = háng reading is the one in 行业 (industry), 银行 (bank), 内行 (insider). Same character, different sense and tone.
register
Closely related: 行话 (hánghuà, same meaning, more common today). 行语 leans literary; 黑话 (hēihuà) implies criminal underworld slang specifically.
