This definition was written to use the ASCII value of the character (81) directly.
To represent all 128 ASCII values, there are actually three subcodes, which can be mixed within a single barcode:
Another method is to convert ASCII numerical values into binary words.
One-byte codes are used only for the ASCII values 0 through 127.
Such as below, word art is created using backslashes and other ASCII values in order to create the illusion of 3D.
"01011001" is the binary representation of the ASCII value of the letter Y.
It is therefore often applied with certain refinements, the most obvious being the conversion of capitals to lowercase before comparing ASCII values.
Alternatively, substituting the letter with its ASCII value makes the resulting number exactly divisible by 9.
The ASCII value of this character is 95.
This is done to prevent the ASCII value falling within the unwanted range 127-199.