Source note · SIP transactions dialogs and call setup

RFC 8217 updates RFC 3515 and RFC 3892 to require that where a SIP header field grammar allows a choice between the name-addr and addr-spec forms, the addr-spec form must not be used if its value would contain a comma, a semicolon or a question mark, and that any URI parameters are contained within angle brackets.

Checked 2026-09-16

the addr-spec form MUST NOT be used if its value would contain a comma, semicolon, or question mark. When a URI appears in such a header field, any URI parameters MUST be contained within angle brackets (< and >).

Vendor: IETF
Product: Session Initiation Protocol
Subsystem: REFER
Deployment: not restricted
Region: not restricted
Release range: Updates RFC 3515
Checked: 2026-09-16

Sources

RFC 8217 — Clarifications for When to Use the name-addr Production in SIP Messages — IETF / RFC Editor · tier 1 standards and regulators · RFC 8217 sections 3 and 4

Cite this note

APA

WarmTransfer. (2026, September 16). SIP transactions dialogs and call setup: source note xfersem-refer-to-must-use-angle-brackets. WarmTransfer. https://warmtransfer.net/knowledge/claims/xfersem-refer-to-must-use-angle-brackets

BibTeX

@misc{warmtransfer-claim-xfersem-refer-to-must-use-angle-brackets,
  title  = {SIP transactions dialogs and call setup: source note xfersem-refer-to-must-use-angle-brackets},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/xfersem-refer-to-must-use-angle-brackets},
  note   = {Source note xfersem-refer-to-must-use-angle-brackets, checked 2026-09-16}
}

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