Human: What is the function of the ‘’ key on the Apple Computer keyboard? Assistant: 
The <unk> key is a modifier key. It’s used to access special characters and functions. It is used to access symbols like the ampersand (&), the left and right parentheses (()), the left and right square brackets ([]), and the vertical bar (|). The <unk> key is also used to access special characters like the copyright symbol (©) and the trademark symbol (™).