|In Unicode||U+24B8 Ⓒ CIRCLED LATIN CAPITAL LETTER C|
U+24D2 ⓒ CIRCLED LATIN SMALL LETTER C
|Different from||U+00A9 © COPYRIGHT SIGN|
The symbols are encoded by Unicode in the block Latin-1 supplement as CIRCLED LATIN CAPITAL LETTER C and CIRCLED LATIN SMALL LETTER C.
Some Chiyoda Kogaku (aka Chiyoko) cameras of the 1947 to 1949 era featured a blue ⓒ symbol as part of the lens designation like in "ⓒ Super Rokkor", e.g. on the Minolta 35 or the Minolta Memo. It was used to indicate a (single) coated optics rather than any copyright. Similar engravings can be found also on lenses of other manufacturers, e.g. some Olympus Zuiko lenses carry a red-colored "Zuiko C." designation indicating coated optics.
This symbol was widely used by the Cruver manufacturing company on their plastic recognition models that were produced during World War II.