Quoted-printable and Base64 are the two basic MIME content transfer encodings. If the input text is mostly ASCII, quoted-printable results in a fairly readable and compact encoded result. On the other hand if the input is not mostly ASCII then quoted-printable becomes both unreadable and extremely inefficient. Base64 is not readable but has a predictable overhead for all data and is the more sensible choice for binary formats or text in non-Latin based languages.
All printable ASCII characters (decimal values between 33 and 126) may be represented by themselves, except "=" (decimal 61).
ASCII tab and space characters, decimal values 9 and 32, may be represented by themselves, except if these characters appear at the end of a line. If one of these characters appears at the end of a line it must be encoded as "=09" (tab) or "=20" (space).
If the data being encoded contains meaningful line breaks, they must be encoded as an ASCII CR LF sequence, not as their original byte values. Conversely if byte values 10 and 13 have meanings other than end of line then they must be encoded as =0A and =0D.
Lines of quoted-printable encoded data must not be longer than 76 characters. To satisfy this requirement without altering the encoded text, soft line breaks may be added as desired. A soft line break consists of an "=" at the end of an encoded line, and does not cause a line break in the decoded text.
Patent Issued for Method and Device for Intercommunicating Address Book Information between Different Networks
Oct 23, 2013; A patent by the inventors Wang, Lei (Shenzhen, CN); Fan, Shunan (Shenzhen, CN); Dong, Ting (Shenzhen, CN); Yang, Jian (Shenzhen,...