Po (Destruction) is a destructive interaction between Earthly Branches, indicating destruction, disarray, and incompleteness. The Six Po relationships are: Zi-Rat and You-Rooster, Wu-Horse and Mao-Rabbit, Si-Snake and Shen-Monkey, Yin-Tiger and Hai-Pig, Chen-Dragon and Chou-Ox, Wei-Sheep and Xu-Dog. Po signifies matters remaining unfulfilled or abandoned midway; however, its force is weaker than that of Clash (Chong), Punishment (Xing), or Harm (Hai).
Examine whether any of the Six Po relationships exist among the Earthly Branches in the four pillars of the八字 (BaZi). The Six Po pairs are: Zi-Rat & You-Rooster, Wu-Horse & Mao-Rabbit, Si-Snake & Shen-Monkey, Yin-Tiger & Hai-Pig, Chen-Dragon & Chou-Ox, Wei-Sheep & Xu-Dog. When any two branches form one of these pairs, Po is present. Po frequently co-occurs with Combination (He); thus, 'Combination with embedded Po' is common.
In a BaZi chart, if Zi-Rat appears in the Year Branch and You-Rooster in the Hour Branch, Zi-You Po occurs, suggesting incompleteness or unresolved matters between youth and old age.