Enclosed Alphanumerics
Many of the symbols were made to be used as bullets when writing lists. The numbers and letters in parentheses were made to look like how typewriters showed numbers and letters in circles. Unicode was made to think that the characters in this block look different than similar copyright symbols (for example, the copyright symbol (left) and the enclosed C (right): © and Ⓒ). The circled S (Ⓢ) was used by German missionaries at around 1900 as a symbol for the ditto mark.