iCalendar Element Registries

Created
2009-04-29
Last Updated
2023-12-06
Note
A Standards Track RFC is required for registration of iCalendar elements that 
modify elements previously documented in a Standards Track RFC.
Available Formats

XML
HTML
Plain text

Registries Included Below

Components

Registration Procedure(s)
Expert Review with RFC Required
Expert(s)
Bernard Desruisseaux, Ken Murchison, Mike Douglass
Reference
[RFC5545]
Available Formats

CSV
Component Status Reference
VCALENDAR Current [RFC5545, Section 3.4]
VEVENT Current [RFC5545, Section 3.6.1]
VTODO Current [RFC5545, Section 3.6.2]
VJOURNAL Current [RFC5545, Section 3.6.3]
VFREEBUSY Current [RFC5545, Section 3.6.4]
VTIMEZONE Current [RFC5545, Section 3.6.5]
VALARM Current [RFC5545, Section 3.6.6]
STANDARD Current [RFC5545, Section 3.6.5]
DAYLIGHT Current [RFC5545, Section 3.6.5]
VAVAILABILITY Current [RFC7953, Section 3.1]
AVAILABLE Current [RFC7953, Section 3.1]
PARTICIPANT Current [RFC9073, Section 7.1]
VLOCATION Current [RFC9073, Section 7.2] [RFC Errata 7381]
VRESOURCE Current [RFC9073, Section 7.3]

Properties

Registration Procedure(s)
Expert Review with RFC Required
Expert(s)
Bernard Desruisseaux, Ken Murchison, Mike Douglass
Reference
[RFC5545]
Available Formats

CSV
Property Status Reference
CALSCALE Current [RFC5545, Section 3.7.1]
METHOD Current [RFC5545, Section 3.7.2]
PRODID Current [RFC5545, Section 3.7.3]
VERSION Current [RFC5545, Section 3.7.4]
ATTACH Current [RFC5545, Section 3.8.1.1]
CATEGORIES Current [RFC5545, Section 3.8.1.2] [RFC7986, Section 5.6]
CLASS Current [RFC5545, Section 3.8.1.3]
COMMENT Current [RFC5545, Section 3.8.1.4]
DESCRIPTION Current [RFC5545, Section 3.8.1.5] [RFC7986, Section 5.2]
GEO Current [RFC5545, Section 3.8.1.6]
LOCATION Current [RFC5545, Section 3.8.1.7]
PERCENT-COMPLETE Current [RFC5545, Section 3.8.1.8]
PRIORITY Current [RFC5545, Section 3.8.1.9]
RESOURCES Current [RFC5545, Section 3.8.1.10]
STATUS Current [RFC5545, Section 3.8.1.11]
SUMMARY Current [RFC5545, Section 3.8.1.12]
COMPLETED Current [RFC5545, Section 3.8.2.1]
DTEND Current [RFC5545, Section 3.8.2.2]
DUE Current [RFC5545, Section 3.8.2.3]
DTSTART Current [RFC5545, Section 3.8.2.4]
DURATION Current [RFC5545, Section 3.8.2.5]
FREEBUSY Current [RFC5545, Section 3.8.2.6]
TRANSP Current [RFC5545, Section 3.8.2.7]
TZID Current [RFC5545, Section 3.8.3.1]
TZNAME Current [RFC5545, Section 3.8.3.2]
TZOFFSETFROM Current [RFC5545, Section 3.8.3.3]
TZOFFSETTO Current [RFC5545, Section 3.8.3.4]
TZURL Current [RFC5545, Section 3.8.3.5]
ATTENDEE Current [RFC5545, Section 3.8.4.1]
CONTACT Current [RFC5545, Section 3.8.4.2]
ORGANIZER Current [RFC5545, Section 3.8.4.3]
RECURRENCE-ID Current [RFC5545, Section 3.8.4.4]
RELATED-TO Current [RFC5545, Section 3.8.4.5] [RFC9253, Section 9.1]
URL Current [RFC5545, Section 3.8.4.6] [RFC7986, Section 5.5]
UID Current [RFC5545, Section 3.8.4.7] [RFC7986, Section 5.3]
EXDATE Current [RFC5545, Section 3.8.5.1]
EXRULE Deprecated [RFC2445, Section 4.8.5.2]
RDATE Current [RFC5545, Section 3.8.5.2]
RRULE Current [RFC5545, Section 3.8.5.3]
ACTION Current [RFC5545, Section 3.8.6.1]
REPEAT Current [RFC5545, Section 3.8.6.2]
TRIGGER Current [RFC5545, Section 3.8.6.3]
CREATED Current [RFC5545, Section 3.8.7.1]
DTSTAMP Current [RFC5545, Section 3.8.7.2]
LAST-MODIFIED Current [RFC5545, Section 3.8.7.3] [RFC7986, Section 5.4]
SEQUENCE Current [RFC5545, Section 3.8.7.4]
REQUEST-STATUS Current [RFC5545, Section 3.8.8.3]
XML Current [RFC6321, Section 4.2]
TZUNTIL Current [RFC7808, Section 7.1]
TZID-ALIAS-OF Current [RFC7808, Section 7.2]
BUSYTYPE Current [RFC7953, Section 3.2]
NAME Current [RFC7986, Section 5.1]
REFRESH-INTERVAL Current [RFC7986, Section 5.7]
SOURCE Current [RFC7986, Section 5.8]
COLOR Current [RFC7986, Section 5.9]
IMAGE Current [RFC7986, Section 5.10]
CONFERENCE Current [RFC7986, Section 5.11]
CALENDAR-ADDRESS Current [RFC9073, Section 6.4]
LOCATION-TYPE Current [RFC9073, Section 6.1]
PARTICIPANT-TYPE Current [RFC9073, Section 6.2]
RESOURCE-TYPE Current [RFC9073, Section 6.3]
STRUCTURED-DATA Current [RFC9073, Section 6.6]
STYLED-DESCRIPTION Current [RFC9073, Section 6.5]
ACKNOWLEDGED Current [RFC9074, Section 6.1]
PROXIMITY Current [RFC9074, Section 8.1]
CONCEPT Current [RFC9253, Section 8.1]
LINK Current [RFC9253, Section 8.2]
REFID Current [RFC9253, Section 8.3]

Parameters

Registration Procedure(s)
Expert Review with RFC Required
Expert(s)
Bernard Desruisseaux, Ken Murchison, Mike Douglass
Reference
[RFC5545]
Available Formats

CSV
Parameter Status Reference
ALTREP Current [RFC5545, Section 3.2.1]
CN Current [RFC5545, Section 3.2.2]
CUTYPE Current [RFC5545, Section 3.2.3]
DELEGATED-FROM Current [RFC5545, Section 3.2.4]
DELEGATED-TO Current [RFC5545, Section 3.2.5]
DIR Current [RFC5545, Section 3.2.6]
ENCODING Current [RFC5545, Section 3.2.7]
FMTTYPE Current [RFC5545, Section 3.2.8]
FBTYPE Current [RFC5545, Section 3.2.9]
LANGUAGE Current [RFC5545, Section 3.2.10]
MEMBER Current [RFC5545, Section 3.2.11]
PARTSTAT Current [RFC5545, Section 3.2.12]
RANGE Current [RFC5545, Section 3.2.13]
RELATED Current [RFC5545, Section 3.2.14]
RELTYPE Current [RFC5545, Section 3.2.15]
ROLE Current [RFC5545, Section 3.2.16]
RSVP Current [RFC5545, Section 3.2.17]
SCHEDULE-AGENT Current [RFC6638, Section 7.1]
SCHEDULE-FORCE-SEND Current [RFC6638, Section 7.2]
SCHEDULE-STATUS Current [RFC6638, Section 7.3]
SENT-BY Current [RFC5545, Section 3.2.18]
TZID Current [RFC5545, Section 3.2.19]
VALUE Current [RFC5545, Section 3.2.20]
DISPLAY Current [RFC7986, Section 6.1]
EMAIL Current [RFC7986, Section 6.2]
FEATURE Current [RFC7986, Section 6.3]
LABEL Current [RFC7986, Section 6.4]
SIZE Current [RFC8607, Section 4.1]
FILENAME Current [RFC8607, Section 4.2]
MANAGED-ID Current [RFC8607, Section 4.3]
ORDER Current [RFC9073, Section 5.1]
SCHEMA Current [RFC9073, Section 5.2]
DERIVED Current [RFC9073, Section 5.3]
GAP Current [RFC9253, Section 6.2]
LINKREL Current [RFC9253, Section 6.1]

Value Data Types

Registration Procedure(s)
Expert Review with RFC Required
Expert(s)
Bernard Desruisseaux, Ken Murchison, Mike Douglass
Reference
[RFC5545]
Note
A Standards Track RFC is REQUIRED for the registration of new Value Data Types that modify
existing properties.
Available Formats

CSV
Value Data Type Status Reference
BINARY Current [RFC5545, Section 3.3.1]
BOOLEAN Current [RFC5545, Section 3.3.2]
CAL-ADDRESS Current [RFC5545, Section 3.3.3]
DATE Current [RFC5545, Section 3.3.4]
DATE-TIME Current [RFC5545, Section 3.3.5]
DURATION Current [RFC5545, Section 3.3.6]
FLOAT Current [RFC5545, Section 3.3.7]
INTEGER Current [RFC5545, Section 3.3.8]
PERIOD Current [RFC5545, Section 3.3.9]
RECUR Current [RFC5545, Section 3.3.10]
TEXT Current [RFC5545, Section 3.3.11]
TIME Current [RFC5545, Section 3.3.12]
UNKNOWN Reserved - Do not use [RFC7265, Section 5]
URI Current [RFC5545, Section 3.3.13]
UTC-OFFSET Current [RFC5545, Section 3.3.14]
XML-REFERENCE Current [RFC9253, Section 7]
UID Current [RFC9253, Section 7]

Calendar User Types

Registration Procedure(s)
Expert Review with RFC Required
Expert(s)
Bernard Desruisseaux, Ken Murchison, Mike Douglass
Reference
[RFC5545]
Available Formats

CSV
Calendar User Type Status Reference
INDIVIDUAL Current [RFC5545, Section 3.2.3]
GROUP Current [RFC5545, Section 3.2.3]
RESOURCE Current [RFC5545, Section 3.2.3]
ROOM Current [RFC5545, Section 3.2.3]
UNKNOWN Current [RFC5545, Section 3.2.3]

Free/Busy Time Types

Registration Procedure(s)
Expert Review with RFC Required
Expert(s)
Bernard Desruisseaux, Ken Murchison, Mike Douglass
Reference
[RFC5545]
Available Formats

CSV
Free/Busy Time Type Status Reference
FREE Current [RFC5545, Section 3.2.9]
BUSY Current [RFC5545, Section 3.2.9]
BUSY-UNAVAILABLE Current [RFC5545, Section 3.2.9]
BUSY-TENTATIVE Current [RFC5545, Section 3.2.9]

Participation Statuses

Registration Procedure(s)
Expert Review with RFC Required
Expert(s)
Bernard Desruisseaux, Ken Murchison, Mike Douglass
Reference
[RFC5545]
Note
A Standards Track RFC is REQUIRED for the registration of Participation Status values 
to be used in "VEVENT" calendar components.
Available Formats

CSV
Participation Status Status Reference
NEEDS-ACTION Current [RFC5545, Section 3.2.12]
ACCEPTED Current [RFC5545, Section 3.2.12]
DECLINED Current [RFC5545, Section 3.2.12]
TENTATIVE Current [RFC5545, Section 3.2.12]
DELEGATED Current [RFC5545, Section 3.2.12]
COMPLETED Current [RFC5545, Section 3.2.12]
IN-PROCESS Current [RFC5545, Section 3.2.12]

Relationship Types

Registration Procedure(s)
Expert Review with RFC Required
Expert(s)
Bernard Desruisseaux, Ken Murchison, Mike Douglass
Reference
[RFC5545]
Available Formats

CSV
Relationship Type Status Reference
CHILD Current [RFC5545, Section 3.2.15]
PARENT Current [RFC5545, Section 3.2.15]
SIBLING Current [RFC5545, Section 3.2.15]
SNOOZE Current [RFC9074, Section 7.1]
CONCEPT Current [RFC9253, Section 5]
DEPENDS-ON Current [RFC9253, Section 5]
FINISHTOFINISH Current [RFC9253, Section 4]
FINISHTOSTART Current [RFC9253, Section 4]
FIRST Current [RFC9253, Section 5]
NEXT Current [RFC9253, Section 5]
REFID Current [RFC9253, Section 5]
STARTTOFINISH Current [RFC9253, Section 4]
STARTTOSTART Current [RFC9253, Section 4]

Participation Roles

Registration Procedure(s)
Expert Review with RFC Required
Expert(s)
Bernard Desruisseaux, Ken Murchison, Mike Douglass
Reference
[RFC5545]
Available Formats

CSV
Role Type Status Reference
CHAIR Current [RFC5545, Section 3.2.16]
REQ-PARTICIPANT Current [RFC5545, Section 3.2.16]
OPT-PARTICIPANT Current [RFC5545, Section 3.2.16]
NON-PARTICIPANT Current [RFC5545, Section 3.2.16]

Actions

Registration Procedure(s)
Expert Review with RFC Required
Expert(s)
Bernard Desruisseaux, Ken Murchison, Mike Douglass
Reference
[RFC5545]
Available Formats

CSV
Action Status Reference
AUDIO Current [RFC5545, Section 3.8.6.1]
DISPLAY Current [RFC5545, Section 3.8.6.1]
EMAIL Current [RFC5545, Section 3.8.6.1]
PROCEDURE Deprecated [RFC2445, Section 4.8.6.1]

Classifications

Registration Procedure(s)
Expert Review with RFC Required
Expert(s)
Bernard Desruisseaux, Ken Murchison, Mike Douglass
Reference
[RFC5545]
Available Formats

CSV
Classification Status Reference
PUBLIC Current [RFC5545, Section 3.8.1.3]
PRIVATE Current [RFC5545, Section 3.8.1.3]
CONFIDENTIAL Current [RFC5545, Section 3.8.1.3]

Methods

Registration Procedure(s)
Expert Review with RFC Required
Expert(s)
Bernard Desruisseaux, Ken Murchison, Mike Douglass
Reference
[RFC5545]
Available Formats

CSV
Method Status Reference
PUBLISH Current [RFC5546]
REQUEST Current [RFC5546]
REPLY Current [RFC5546]
ADD Current [RFC5546]
CANCEL Current [RFC5546]
REFRESH Current [RFC5546]
COUNTER Current [RFC5546]
DECLINECOUNTER Current [RFC5546]

REQUEST-STATUS Values

Registration Procedure(s)
Expert Review with RFC Required
Expert(s)
Bernard Desruisseaux, Ken Murchison, Mike Douglass
Reference
[RFC5546]
Available Formats

CSV
Status Code Status Reference
1.0 Current [RFC6638, Section 3.2.9.1]
1.1 Current [RFC6638, Section 3.2.9.2]
1.2 Current [RFC6638, Section 3.2.9.3]
2.0 Current [RFC5546, Section 3.6.1]
2.1 Current [RFC5546, Section 3.6.2]
2.2 Current [RFC5546, Section 3.6.3]
2.3 Current [RFC5546, Section 3.6.4]
2.4 Current [RFC5546, Section 3.6.5]
2.5 Current [RFC5546, Section 3.6.6]
2.6 Current [RFC5546, Section 3.6.7]
2.7 Current [RFC5546, Section 3.6.8]
2.8 Current [RFC5546, Section 3.6.9]
2.9 Current [RFC5546, Section 3.6.10]
2.10 Current [RFC5546, Section 3.6.11]
2.11 Current [RFC5546, Section 3.6.12]
3.0 Current [RFC5546, Section 3.6.13]
3.1 Current [RFC5546, Section 3.6.14]
3.2 Current [RFC5546, Section 3.6.15]
3.3 Current [RFC5546, Section 3.6.16]
3.4 Current [RFC5546, Section 3.6.17]
3.5 Current [RFC5546, Section 3.6.18]
3.6 Current [RFC5546, Section 3.6.19]
3.7 Current [RFC5546, Section 3.6.20]
3.8 Current [RFC5546, Section 3.6.21]
3.9 Current [RFC5546, Section 3.6.22]
3.10 Current [RFC5546, Section 3.6.23]
3.11 Current [RFC5546, Section 3.6.24]
3.12 Current [RFC5546, Section 3.6.25]
3.13 Current [RFC5546, Section 3.6.26]
3.14 Current [RFC5546, Section 3.6.27]
4.0 Current [RFC5546, Section 3.6.28]
5.0 Current [RFC5546, Section 3.6.29]
5.1 Current [RFC5546, Section 3.6.30]
5.2 Current [RFC5546, Section 3.6.31]
5.3 Current [RFC5546, Section 3.6.32]

Schedule Agent Values Registry

Registration Procedure(s)
Expert Review with RFC Required
Expert(s)
Unassigned
Reference
[RFC6638]
Available Formats

CSV
Schedule Agent Status Reference
SERVER Current [RFC6638, Section 7.1]
CLIENT Current [RFC6638, Section 7.1]
NONE Current [RFC6638, Section 7.1]

Schedule Force Send Values Registry

Registration Procedure(s)
Expert Review with RFC Required
Expert(s)
Unassigned
Reference
[RFC6638]
Available Formats

CSV
Schedule Force Send Status Reference
REQUEST Current [RFC6638, Section 7.2]
REPLY Current [RFC6638, Section 7.2]

Display Types

Registration Procedure(s)
Expert Review with RFC Required
Expert(s)
Unassigned
Reference
[RFC7986]
Available Formats

CSV
Display Type Status Reference
BADGE Current [RFC7986, Section 6.1]
GRAPHIC Current [RFC7986, Section 6.1]
FULLSIZE Current [RFC7986, Section 6.1]
THUMBNAIL Current [RFC7986, Section 6.1]

Feature Types

Registration Procedure(s)
Expert Review with RFC Required
Expert(s)
Unassigned
Reference
[RFC7986]
Available Formats

CSV
Name Status Reference
AUDIO Current [RFC7986, Section 6.3]
CHAT Current [RFC7986, Section 6.3]
FEED Current [RFC7986, Section 6.3]
MODERATOR Current [RFC7986, Section 6.3]
PHONE Current [RFC7986, Section 6.3]
SCREEN Current [RFC7986, Section 6.3]
VIDEO Current [RFC7986, Section 6.3]

Participant Types

Registration Procedure(s)
Expert Review
Expert(s)
Ken Murchison, Michael Douglass
Reference
[RFC9073]
Available Formats

CSV
Participant Type Status Reference
ACTIVE Current [RFC9073, Section 6.2]
INACTIVE Current [RFC9073, Section 6.2]
SPONSOR Current [RFC9073, Section 6.2]
CONTACT Current [RFC9073, Section 6.2]
BOOKING-CONTACT Current [RFC9073, Section 6.2]
EMERGENCY-CONTACT Current [RFC9073, Section 6.2]
PUBLICITY-CONTACT Current [RFC9073, Section 6.2]
PLANNER-CONTACT Current [RFC9073, Section 6.2]
PERFORMER Current [RFC9073, Section 6.2]
SPEAKER Current [RFC9073, Section 6.2]

Resource Types

Registration Procedure(s)
Expert Review
Expert(s)
Ken Murchison, Michael Douglass
Reference
[RFC9073]
Available Formats

CSV
Resource Type Status Reference
PROJECTOR Current [RFC9073, Section 6.3]
ROOM Current [RFC9073, Section 6.3]
REMOTE-CONFERENCE-AUDIO Current [RFC9073, Section 6.3]
REMOTE-CONFERENCE-VIDEO Current [RFC9073, Section 6.3]

Proximity Values

Registration Procedure(s)
Expert Review with RFC Required
Expert(s)
Ken Murchison, Michael Douglass
Reference
[RFC9074]
Available Formats

CSV
Value Status Reference
ARRIVE Current [RFC9074, Section 8.1]
DEPART Current [RFC9074, Section 8.1]
CONNECT Current [RFC9074, Section 8.1]
DISCONNECT Current [RFC9074, Section 8.1]