Quoted-Printable
The format Quoted-Printable is a format of encoding of text given coded on 8 bits, which exclusively uses the printable alphanumerics of the code ASCII.
Indeed, various codings include/understand many characters which are not representable in ASCII (for examples accentuated characters), as well as characters known as " non-imprimables".
The encoding Quoted-Printable makes it possible to cure this problem, while proceeding in the following way:
- a byte corresponding to a printable character is represented such as it is
- a byte which does not correspond to a printable character of the ASCII is represented by an equal sign, followed of its number, expressed in Hexadécimal.
An example: the character " é" is represented in Latin-9 by a value of 233. 233 is written " E9" into hexadecimal, the character " é" will thus be represented by " =E9" under the Quoted-Printable format.
Another example, for a sentence, encodée in Latin-9:
" This text will be encodé in Quoted-Printable" give: " This text goes =EAtre encod=E9 in Quoted-Printable"
The Quoted-Printable format makes it possible to preserve the essence of the legibility of the message, contrary to coding Base64. These two codings are in particular used in the part MIME of e-mail.