Quoted-printable
BINARY-TO-TEXT ENCODING
Quoted printable; Quoted printable encoding; Quoted Printable; Quoted-Printable; QP Encoding; =3D; =09; Quopri
Quoted-Printable, or QP encoding, is a binary-to-text encoding system using printable ASCII characters (alphanumeric and the equals sign =) to transmit 8-bit data over a 7-bit data path or, generally, over a medium which is not 8-bit clean. Historically, because of the wide range of systems and protocols that could be used to transfer messages, e-mail was often assumed to be non-8-bit-clean – however, modern SMTP servers are in most cases 8-bit clean and support 8BITMIME extension.