Hollow outlined circle, used as a bullet, empty radio button, or maru mark meaning correct in Japan; also taian in Rokuyō calendars.
96 characters in the Geometric Shapes Unicode block.
U+25A0BLACK SQUAREU+25A1WHITE SQUAREU+25A2WHITE SQUARE WITH ROUNDED CORNERSU+25A3WHITE SQUARE CONTAINING BLACK SMALL SQUAREU+25A4SQUARE WITH HORIZONTAL FILLU+25A5SQUARE WITH VERTICAL FILLU+25A6SQUARE WITH ORTHOGONAL CROSSHATCH FILLU+25A7SQUARE WITH UPPER LEFT TO LOWER RIGHT FILLU+25A8SQUARE WITH UPPER RIGHT TO LOWER LEFT FILLU+25A9SQUARE WITH DIAGONAL CROSSHATCH FILLU+25AABLACK SMALL SQUAREU+25ABWHITE SMALL SQUAREU+25ACBLACK RECTANGLEU+25ADWHITE RECTANGLEU+25AEBLACK VERTICAL RECTANGLEU+25AFWHITE VERTICAL RECTANGLEU+25B0BLACK PARALLELOGRAMU+25B1WHITE PARALLELOGRAMU+25B2BLACK UP-POINTING TRIANGLEU+25B3WHITE UP-POINTING TRIANGLEU+25B4BLACK UP-POINTING SMALL TRIANGLEU+25B5WHITE UP-POINTING SMALL TRIANGLEU+25B6BLACK RIGHT-POINTING TRIANGLEU+25B7WHITE RIGHT-POINTING TRIANGLEU+25B8BLACK RIGHT-POINTING SMALL TRIANGLEU+25B9WHITE RIGHT-POINTING SMALL TRIANGLEU+25BABLACK RIGHT-POINTING POINTERU+25BBWHITE RIGHT-POINTING POINTERU+25BCBLACK DOWN-POINTING TRIANGLEU+25BDWHITE DOWN-POINTING TRIANGLEU+25BEBLACK DOWN-POINTING SMALL TRIANGLEU+25BFWHITE DOWN-POINTING SMALL TRIANGLEU+25C0BLACK LEFT-POINTING TRIANGLEU+25C1WHITE LEFT-POINTING TRIANGLEU+25C2BLACK LEFT-POINTING SMALL TRIANGLEU+25C3WHITE LEFT-POINTING SMALL TRIANGLEU+25C4BLACK LEFT-POINTING POINTERU+25C5WHITE LEFT-POINTING POINTERU+25C6BLACK DIAMONDU+25C7WHITE DIAMONDU+25C8WHITE DIAMOND CONTAINING BLACK SMALL DIAMONDU+25C9FISHEYEU+25CALOZENGEU+25CBWHITE CIRCLEU+25CCDOTTED CIRCLEU+25CDCIRCLE WITH VERTICAL FILLU+25CEBULLSEYEU+25CFBLACK CIRCLEU+25D0CIRCLE WITH LEFT HALF BLACKU+25D1CIRCLE WITH RIGHT HALF BLACKU+25D2CIRCLE WITH LOWER HALF BLACKU+25D3CIRCLE WITH UPPER HALF BLACKU+25D4CIRCLE WITH UPPER RIGHT QUADRANT BLACKU+25D5CIRCLE WITH ALL BUT UPPER LEFT QUADRANT BLACKU+25D6LEFT HALF BLACK CIRCLEU+25D7RIGHT HALF BLACK CIRCLEU+25D8INVERSE BULLETU+25D9INVERSE WHITE CIRCLEU+25DAUPPER HALF INVERSE WHITE CIRCLEU+25DBLOWER HALF INVERSE WHITE CIRCLEU+25DCUPPER LEFT QUADRANT CIRCULAR ARCU+25DDUPPER RIGHT QUADRANT CIRCULAR ARCU+25DELOWER RIGHT QUADRANT CIRCULAR ARCU+25DFLOWER LEFT QUADRANT CIRCULAR ARCU+25E0UPPER HALF CIRCLEU+25E1LOWER HALF CIRCLEU+25E2BLACK LOWER RIGHT TRIANGLEU+25E3BLACK LOWER LEFT TRIANGLEU+25E4BLACK UPPER LEFT TRIANGLEU+25E5BLACK UPPER RIGHT TRIANGLEU+25E6WHITE BULLETU+25E7SQUARE WITH LEFT HALF BLACKU+25E8SQUARE WITH RIGHT HALF BLACKU+25E9SQUARE WITH UPPER LEFT DIAGONAL HALF BLACKU+25EASQUARE WITH LOWER RIGHT DIAGONAL HALF BLACKU+25EBWHITE SQUARE WITH VERTICAL BISECTING LINEU+25ECWHITE UP-POINTING TRIANGLE WITH DOTU+25EDUP-POINTING TRIANGLE WITH LEFT HALF BLACKU+25EEUP-POINTING TRIANGLE WITH RIGHT HALF BLACKU+25EFLARGE CIRCLEU+25F0WHITE SQUARE WITH UPPER LEFT QUADRANTU+25F1WHITE SQUARE WITH LOWER LEFT QUADRANTU+25F2WHITE SQUARE WITH LOWER RIGHT QUADRANTU+25F3WHITE SQUARE WITH UPPER RIGHT QUADRANTU+25F4WHITE CIRCLE WITH UPPER LEFT QUADRANTU+25F5WHITE CIRCLE WITH LOWER LEFT QUADRANTU+25F6WHITE CIRCLE WITH LOWER RIGHT QUADRANTU+25F7WHITE CIRCLE WITH UPPER RIGHT QUADRANTU+25F8UPPER LEFT TRIANGLEU+25F9UPPER RIGHT TRIANGLEU+25FALOWER LEFT TRIANGLEU+25FBWHITE MEDIUM SQUAREU+25FCBLACK MEDIUM SQUAREU+25FDWHITE MEDIUM SMALL SQUAREU+25FEBLACK MEDIUM SMALL SQUAREU+25FFLOWER RIGHT TRIANGLE