Parse values without splitting quoted commas
02A Link field can contain several link-values, and each value can contain parameters. Delimiters inside quoted text belong to that text.
In </one>; rel="next"; rel="prev", the second rel MUST be ignored. The first next relation remains; this does not create both next and prev links.
Source for this drawing: RFC 8288 · 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
- link-value
- One target and its parameter list in a Link field.
- Quoted string
- Text surrounded by double quotes, with defined escaping rules.
Related RFCs and changes
“Updates” changes part of an earlier RFC. “Obsoletes” replaces it. This list shows selected related documents.
A link-value begins with a URI-reference inside angle brackets, then zero or more semicolon-delimited parameters. Multiple link-values form a comma-separated field list.
- A link-value begins with a URI-reference inside angle brackets, then zero or more semicolon-delimited parameters. Multiple link-values form a comma-separated field list.
- Recipients MUST parse both token and quoted-string parameter forms, such as rel=next and rel="next". Unquote before interpreting a parameter’s value.
- The rel parameter MUST be present and MUST NOT appear more than once in a link-value. Parsers MUST ignore occurrences after the first; they do not merge duplicate rel parameters.
- A single rel value may contain space-separated relation types. That creates multiple links sharing the same context, target and attributes; it is different from repeated rel parameters.
The example title="One, two" contains a literal comma, not a link separator. A parser must respect quoted-string escaping and angle-bracket boundaries; naive splitting on every comma or semicolon is insufficient. Separate Link fields can carry the same link-values as a combined field. Appendix B is advisory, not a replacement for the normative body; verified erratum 5878 corrects its target-attribute handling.
Read the RFC section ↗