The Left Angle Cross of Identification is named for Gate 16 and Gate 9. Human Design reads Gate 16, from Hexagram 16, Enthusiasm, sits in the Throat and is read as a natural talent refined by repetition into real skill; and Gate 9, from Hexagram 9, Small Taming, sits in the Sacral centre and is read as the capacity to attend to the small details a larger idea depends on. It sits in the Left Angle family, and Human Design reads that group as outward facing, less a chosen plan than a role other people keep handing back.
Its design half is Gate 63 and Gate 64, both seated in the Head. Gate 63 is read as doubt, the pressure to question and look for the flaw in a pattern before accepting it; it pairs with Gate 4 in the channel of Logic. Gate 64 is read as confusion, unresolved images working themselves slowly toward a clarity that arrives on its own schedule; it pairs with Gate 47 in the channel of Abstraction.
So a chart carrying this cross practises a skill built by repeated small attention on the surface, while beneath it a Head pair of doubt and confusion presses toward a clarity neither gate can force on its own schedule. The hexagrams are ancient; grouping four of them into one transpersonal cross is the modern system's own construction, dated to 1987.