What is Six Relatives?

The Six Relatives are five relational roles assigned to each hexagram line based on its Five Element's relationship to the hexagram's palace element. Brothers (兄弟) share the same element. Offspring (子孫) are generated by it. Wife's Wealth (妻財) is controlled by it. Officer/Ghost (官鬼) controls it. Parents (父母) generate it. These roles determine how each line functions in a reading — which line represents wealth, career, health, or the querent.

Source: Bushi Zhengzong (卜筮正宗), Wang Hongxu, 1709