Treat related parts as one object
01A compound object needs its related parts to be interpreted together. MIME means Multipurpose Internet Mail Extensions: a format for labeling message content.
The HTML application combines the selected root with its resource. Showing the two parts independently would not reproduce this example’s intended presentation.
Source for this drawing: RFC 2387 · Read RFC section 3 ↗
New to this? Start hereA quick picture + helpful background
A message needs an address.
Think of a packet as a small addressed envelope. Devices pass it onward; transport protocols decide what delivery promises an application gets.
Helpful first, if these ideas are unfamiliar
These pictures are analogies to help you learn. The linked RFC explains the actual rules.
Terms in this drawing
Related RFCs and changes
“Updates” changes part of an earlier RFC. “Obsoletes” replaces it. This list shows selected related documents.
Multipart/Related describes an aggregate of interdependent body parts, not just a list of unrelated attachments. Like other multipart bodies, it also needs a boundary parameter and matching delimiter lines under RFC 2046.
- Multipart/Related describes an aggregate of interdependent body parts, not just a list of unrelated attachments. Like other multipart bodies, it also needs a boundary parameter and matching delimiter lines under RFC 2046.
- The root is the part the application processes first. Other parts can supply resources used by that root.
- Links between parts belong to the compound format. A cid URL is one possible link mechanism, specified separately in RFC 2392.
Fictional .example identifiers and omitted payloads. These are simplified illustrations, not complete importable messages or a full MIME parser.
Read the RFC section ↗