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RFC 2045 / MECHANISM GUIDE

Quoted-printable bytes

03

Quoted-printable preserves much readable ASCII while encoding other octets as equals plus hex.

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“Updates” changes part of an earlier RFC. “Obsoletes” replaces it. This list shows selected related documents.

DIAGRAM§ 6.7 ↗
RFC 2045 · § 6.7EXAMPLE
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Quoted-printable bytesQuoted-printable preserves much readable ASCII while encoding other octets as equals plus hex.Quoted-printable bytesOriginal octet: =quoted-printable=3Dlong logical line =continued after soft breakDecode transport bytes before charset interpretation
03
Decode the content

Undo transport encoding before applying text interpretation.

Protocol participantThreat or exceptionProtocol controlSimplified drawings · precise section references
KEY POINT

An encoded octet uses = followed by two uppercase hexadecimal digits.

  • An encoded octet uses = followed by two uppercase hexadecimal digits.
  • A soft line break ends with = and is removed during decoding.
  • Encoded lines are limited to 76 characters, excluding CRLF.
DETAILS

Examples are illustrative. Consult the linked RFC and its errata for implementation details.

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Diagrams simplify the RFC. Read the linked sections for complete requirements.

Privacy
All chapters in this RFC
  1. MIME entity headers
  2. Content type and charset
  3. Quoted-printable bytes
  4. Base64 body encoding
  5. Canonical form and safety
RFC 9700 / CHAPTERS

Chapters

For full details, tables, algorithms, and exceptions, read the original RFC.

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