Combining Diacritical Marks for Symbols characters supported by the FreeSerif Bold font

Character	Image
COMBINING LEFT HARPOON ABOVE (U+20D0)
COMBINING RIGHT HARPOON ABOVE (U+20D1)
COMBINING LEFT ARROW ABOVE (U+20D6)
COMBINING RIGHT ARROW ABOVE (U+20D7)
COMBINING THREE DOTS ABOVE (U+20DB)
COMBINING FOUR DOTS ABOVE (U+20DC)
COMBINING ENCLOSING CIRCLE (U+20DD)
COMBINING ENCLOSING SQUARE (U+20DE)
COMBINING ENCLOSING DIAMOND (U+20DF)
COMBINING ENCLOSING CIRCLE BACKSLASH (U+20E0)
COMBINING LEFT RIGHT ARROW ABOVE (U+20E1)
COMBINING REVERSE SOLIDUS OVERLAY (U+20E5)
COMBINING ANNUITY SYMBOL (U+20E7)
COMBINING TRIPLE UNDERDOT (U+20E8)
COMBINING LEFTWARDS ARROW OVERLAY (U+20EA)
COMBINING LONG DOUBLE SOLIDUS OVERLAY (U+20EB)
COMBINING RIGHTWARDS HARPOON WITH BARB DOWNWARDS (U+20EC)
COMBINING LEFTWARDS HARPOON WITH BARB DOWNWARDS (U+20ED)
COMBINING LEFT ARROW BELOW (U+20EE)
COMBINING RIGHT ARROW BELOW (U+20EF)

Count: 20

Character
COMBINING LONG VERTICAL LINE OVERLAY (U+20D2)
COMBINING SHORT VERTICAL LINE OVERLAY (U+20D3)
COMBINING ANTICLOCKWISE ARROW ABOVE (U+20D4)
COMBINING CLOCKWISE ARROW ABOVE (U+20D5)
COMBINING RING OVERLAY (U+20D8)
COMBINING CLOCKWISE RING OVERLAY (U+20D9)
COMBINING ANTICLOCKWISE RING OVERLAY (U+20DA)
COMBINING ENCLOSING SCREEN (U+20E2)
COMBINING ENCLOSING KEYCAP (U+20E3)
COMBINING ENCLOSING UPWARD POINTING TRIANGLE (U+20E4)
COMBINING DOUBLE VERTICAL STROKE OVERLAY (U+20E6)
COMBINING WIDE BRIDGE ABOVE (U+20E9)
COMBINING ASTERISK ABOVE (U+20F0)

Count: 13