Tiny SYN letters standing for synchronous idle, a data communication control code shown visibly.
U+2415SYMBOL FOR NEGATIVE ACKNOWLEDGEU+2417SYMBOL FOR END OF TRANSMISSION BLOCKU+2414SYMBOL FOR DEVICE CONTROL FOURU+2418SYMBOL FOR CANCELU+2413SYMBOL FOR DEVICE CONTROL THREEU+2419SYMBOL FOR END OF MEDIUMU+2412SYMBOL FOR DEVICE CONTROL TWOU+241ASYMBOL FOR SUBSTITUTEU+2411SYMBOL FOR DEVICE CONTROL ONEU+241BSYMBOL FOR ESCAPEU+2410SYMBOL FOR DATA LINK ESCAPEU+241CSYMBOL FOR FILE SEPARATOR42 characters in the Control Pictures Unicode block.
U+2400SYMBOL FOR NULLU+2401SYMBOL FOR START OF HEADINGU+2402SYMBOL FOR START OF TEXTU+2403SYMBOL FOR END OF TEXTU+2404SYMBOL FOR END OF TRANSMISSIONU+2405SYMBOL FOR ENQUIRYU+2406SYMBOL FOR ACKNOWLEDGEU+2407SYMBOL FOR BELLU+2408SYMBOL FOR BACKSPACEU+2409SYMBOL FOR HORIZONTAL TABULATIONU+240ASYMBOL FOR LINE FEEDU+240BSYMBOL FOR VERTICAL TABULATIONU+240CSYMBOL FOR FORM FEEDU+240DSYMBOL FOR CARRIAGE RETURNU+240ESYMBOL FOR SHIFT OUTU+240FSYMBOL FOR SHIFT INU+2410SYMBOL FOR DATA LINK ESCAPEU+2411SYMBOL FOR DEVICE CONTROL ONEU+2412SYMBOL FOR DEVICE CONTROL TWOU+2413SYMBOL FOR DEVICE CONTROL THREEU+2414SYMBOL FOR DEVICE CONTROL FOURU+2415SYMBOL FOR NEGATIVE ACKNOWLEDGEU+2416SYMBOL FOR SYNCHRONOUS IDLEU+2417SYMBOL FOR END OF TRANSMISSION BLOCKU+2418SYMBOL FOR CANCELU+2419SYMBOL FOR END OF MEDIUMU+241ASYMBOL FOR SUBSTITUTEU+241BSYMBOL FOR ESCAPEU+241CSYMBOL FOR FILE SEPARATORU+241DSYMBOL FOR GROUP SEPARATORU+241ESYMBOL FOR RECORD SEPARATORU+241FSYMBOL FOR UNIT SEPARATORU+2420SYMBOL FOR SPACEU+2421SYMBOL FOR DELETEU+2422BLANK SYMBOLU+2423OPEN BOXU+2424SYMBOL FOR NEWLINEU+2425SYMBOL FOR DELETE FORM TWOU+2426SYMBOL FOR SUBSTITUTE FORM TWOU+2427SYMBOL FOR DELETE SQUARE CHECKER BOARD FORMU+2428SYMBOL FOR DELETE RECTANGULAR CHECKER BOARD FORMU+2429SYMBOL FOR DELETE MEDIUM SHADE FORM