U+1D306 Tetragram for Centre

The Wikipedia has the following information about this codepoint:

The text Tài Xuán Jīng ("Canon of Supreme Mystery", Chinese: 太玄經) is a guide for divination composed by the Confucian writer Yang Xiong (53 BCE – 18 CE). The first draft of this work was completed in 2 BCE (in the decade before the fall of the Western Han dynasty). During the Jin dynasty, an otherwise unknown person named Fan Wang (Chinese: 范望) salvaged the text and wrote a commentary on it, from which our text survives today.

The Taixuanjing is a divinatory text similar to, and inspired by, the I Ching (Yijing). Whereas the I Ching is based on 64 binary hexagrams (sequences of six horizontal lines each of which may be broken or unbroken), the Taixuanjing employs 81 ternary tetragrams (sequences of four lines, each of which may be unbroken, broken once, or broken twice). Like the I Ching it may be consulted as an oracle by casting yarrow stalks or a six-faced die to generate numbers which define the lines of a tetragram, which can then be looked up in the text. A tetragram drawn without moving lines refers to the tetragram description, while a tetragram drawn with moving lines refers to the specific lines.

The monograms are:

• the unbroken line ( ⚊) for heaven (Chinese: 天; pinyin: tiān),
• once broken line ( ⚋) for earth (Chinese: 地; pinyin: dì),
• twice broken line ( 𝌀) for man (Chinese: 人; pinyin: rén).

Numerically the symbols can be counted as ⚊ = 0, ⚋ = 1, 𝌀 = 2, and grouped into sets of four to count from 0 to 80. This is clearly intentional as this passage from chapter 8 of the Tài Xuán Jīng points out the principle of carrying and place value.