RFC 5545, "Internet Calendaring and Scheduling Core Object Specification (iCalendar)", September 2009

Note: This RFC has been updated by RFC 5546, RFC 6868, RFC 7529, RFC 7953, RFC 7986, RFC 9073, RFC 9074, RFC 9253

Errata ID: 5214
Status: Rejected
Type: Technical
Publication Format(s) : TEXT
Reported By: Richard Smith
Date Reported: 2017-12-24
Rejected by: Francesca Palombini
Date Rejected: 2024-01-16

Section 3.6.5 says:

       timezonec  = "BEGIN" ":" "VTIMEZONE" CRLF
                    *(
                    ;
                    ; 'tzid' is REQUIRED, but MUST NOT occur more
                    ; than once.
                    ;
                    tzid /
                    ;
                    ; 'last-mod' and 'tzurl' are OPTIONAL,
                    ; but MUST NOT occur more than once.
                    ;
                    last-mod / tzurl /
                    ;
                    ; One of 'standardc' or 'daylightc' MUST occur
                    ; and each MAY occur more than once.
                    ;
                    standardc / daylightc /
                    ;
                    ; The following are OPTIONAL,
                    ; and MAY occur more than once.
                    ;
                    x-prop / iana-prop
                    ;
                    )
                    "END" ":" "VTIMEZONE" CRLF

It should say:

       timezonec    = "BEGIN" ":" "VTIMEZONE" CRLF
                      timezoneprop timezonesubc
                      "END" ":" "VTIMEZONE" CRLF

       timezoneprop = *(
                      ;
                      ; 'tzid' is REQUIRED, but MUST NOT occur more
                      ; than once.
                      ;
                      tzid /
                      ;
                      ; 'last-mod' and 'tzurl' are OPTIONAL,
                      ; but MUST NOT occur more than once.
                      ;
                      last-mod / tzurl /
                      ;
                      ; The following are OPTIONAL,
                      ; and MAY occur more than once.
                      ;
                      x-prop / iana-prop
                      ;

       timezonesubc = *(
                      ;
                      ; One of 'standardc' or 'daylightc' MUST occur
                      ; and each MAY occur more than once.
                      ;
                      standardc / daylightc
                      ;
                      )

Notes:

The definition of icalbody shows that calendar properties precede components. Some components may contains sub-components. For those that may:

The definition of eventc (section 3.6.1 - Event Component) also shows that properties precede sub-components.

The definition of todoc (section 3.6.2 - To-Do Component) also shows that properties precede sub-components.

However, the definition of timezonec (section 3.6.5 - Time Zone Component) shows that properties and sub-components may be intermingled. The corrected text assumes this was not intended.
--VERIFIER NOTES--
The current ABNF doesn't appear to cause any interop problems, given that both ical4j and libical don't care about the order of properties and components within a VTIMEZONE component.

See https://mailarchive.ietf.org/arch/msg/calsify/x82GopunVcEh8y5UGSIsEIC3s6M/

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