The ITh signifies the speaker. In AL: I the speaker is Nuit, and Hadit is diminished to Had; in AL: II the speaker is Hadit, and Nuit is diminished to "Nu". Both are always present; the position of the ITh determines the focus.
(When the focus is on both, or neither (0 = 2), Had and Nu are referred to as Ra Hoor Khuit, their conjunction.*)
Why is ITh appropriate?
Greek gematria:
NF (Nu) = 56 ("My word is six and fifty")
HAD = 13
ITh = 19
NFITh = 75
HADITh = 32
(56 + 13 = 69) + 19 = 88
NFITh + HAD or NF + HADITh = 88
61 the Jews call it; I call it 8, 80, 418
What, then, is ITh? ITh is Iota Theta. Hieroglyphically, Iota is a symbol of the Mahalingam, a vertical line. Theta is a circle bisected by a horizontal line. Combined, so that Iota bisects the circle of Theta, they form a cross, surrounded by a circle.
Therefore, Theta alone symbolizes Nuit; Iota alone symbolizes Hadit; their conjunction symbolizes Ra Hoor Khuit.
This circle squared, in its failure, is a key also
* In the Book of the Law, also, we find the variant Ra Hoor Khu
, where the ITh is missing also. I find myself at a loss to explain the doctrine behind this variant.