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2) Once selected, you can just type Latin characters as usual. Unicode Hex Input provides basic Latin text input as you would expect. The interesting part is inputting four-digit hexadecimal Unicode scalar values.
To do this, keep the ⌥ Option key depressed (sometimes called the Alt key; look out for the ⌥ symbol), and type the four hexadecimal digits of the Unicode character you wish to insert. When it appears you can let go of the Option key.

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