2. The method of processing information according to claim 1 , further comprising a preliminary operation including defining a plurality of character fonts and in assigning a dedicated digital code to each font of the plurality of character fonts, in that the coding operation further comprises, for each character, the operation of choosing a specific font among said plurality of fonts, and in that the printing operation further comprises, for each character, the operation of printing, in a predetermined position of the character, at least one dot coding the specific font, wherein the representation power of each character is extended.
3. The method of processing information according to claim 2 , wherein the header comprises an alternating succession of black dots and mixed dots, mixed dots comprising a half black dot and a half white dot, or an absence of black dots in order to form a crenellated line.