duodecimal notation(n = noun.communication) - any notation that uses 12 different characters;
is a kind of mathematical notation

binary notation, chemical notation, decimal notation, duodecimal, duodecimal digit, duodecimal number system, duodecimal system, fixed-point notation, floating-point notation, hexadecimal notation, infix notation, lukasiewicz notation, mathematical notation, musical notation, notation, octal notation, parenthesis-free notation, polish notation, positional notation, postfix notation, prefix notation, reverse polish notation, sexadecimal notation, suffix notation