RFC 5318, "The Session Initiation Protocol (SIP) P-Refused-URI-List Private-Header (P-Header)", December 2008Source of RFC: IETF - NON WORKING GROUP
Area Assignment: gen
Errata ID: 4651
Reported By: Brett Tate
Date Reported: 2016-03-29
Section 5 says:
The members P-Header parameter MUST contain a cid-url, which is defined in RFC 2392 .
It should say:
The members P-Header parameter MUST contain a cid-url, which is defined in RFC 2392 . If the URI contains a comma, question mark or semicolon, the URI MUST be enclosed in angle brackets (< and >).
Comma and semicolon can cause decode ambiguities when the header contains addr-spec values instead of name-addr values. For consistency with RFC 3261 section 20, the same bracket rule is indicated to resolve the ambiguity.