iCalendar Element Registries
Created
- 2009-04-29
Last Updated
- 2026-03-26
Note
A Standards Track RFC is required for registration of iCalendar elements that modify elements previously documented in a Standards Track RFC.
Available Formats
Components
Registration Procedure(s)
- Expert Review with RFC Required
Expert(s)
- Bernard Desruisseaux, Ken Murchison, Mike Douglass
Reference
- RFC 5545: Internet Calendaring and Scheduling Core Object Specification (iCalendar)
Available Formats
| Component | Status | Reference |
|---|---|---|
| VCALENDAR | Current | RFC 5545, Section 3.4 |
| VEVENT | Current | RFC 5545, Section 3.6.1 |
| VTODO | Current | RFC 5545, Section 3.6.2 |
| VJOURNAL | Current | RFC 5545, Section 3.6.3 |
| VFREEBUSY | Current | RFC 5545, Section 3.6.4 |
| VTIMEZONE | Current | RFC 5545, Section 3.6.5 |
| VALARM | Current | RFC 5545, Section 3.6.6 |
| STANDARD | Current | RFC 5545, Section 3.6.5 |
| DAYLIGHT | Current | RFC 5545, Section 3.6.5 |
| VAVAILABILITY | Current | RFC 7953, Section 3.1 |
| AVAILABLE | Current | RFC 7953, Section 3.1 |
| PARTICIPANT | Current | RFC 9073, Section 7.1 |
| VLOCATION | Current | RFC 9073, Section 7.2; RFC Errata 7381 |
| VRESOURCE | Current | RFC 9073, Section 7.3 |
| VSTATUS | Current | RFC-ietf-calext-ical-tasks-17, Section 12.1 |
Properties
Registration Procedure(s)
- Expert Review with RFC Required
Expert(s)
- Bernard Desruisseaux, Ken Murchison, Mike Douglass
Reference
- RFC 5545: Internet Calendaring and Scheduling Core Object Specification (iCalendar)
Available Formats
Parameters
Registration Procedure(s)
- Expert Review with RFC Required
Expert(s)
- Bernard Desruisseaux, Ken Murchison, Mike Douglass
Reference
- RFC 5545: Internet Calendaring and Scheduling Core Object Specification (iCalendar)
Available Formats
Value Data Types
Registration Procedure(s)
- Expert Review with RFC Required
Expert(s)
- Bernard Desruisseaux, Ken Murchison, Mike Douglass
Reference
- RFC 5545: Internet Calendaring and Scheduling Core Object Specification (iCalendar)
Note
A Standards Track RFC is REQUIRED for the registration of new Value Data Types that modify existing properties.
Available Formats
| Value Data Type | Status | Reference |
|---|---|---|
| BINARY | Current | RFC 5545, Section 3.3.1 |
| BOOLEAN | Current | RFC 5545, Section 3.3.2 |
| CAL-ADDRESS | Current | RFC 5545, Section 3.3.3 |
| DATE | Current | RFC 5545, Section 3.3.4 |
| DATE-TIME | Current | RFC 5545, Section 3.3.5 |
| DURATION | Current | RFC 5545, Section 3.3.6 |
| FLOAT | Current | RFC 5545, Section 3.3.7 |
| INTEGER | Current | RFC 5545, Section 3.3.8 |
| PERIOD | Current | RFC 5545, Section 3.3.9 |
| RECUR | Current | RFC 5545, Section 3.3.10 |
| TEXT | Current | RFC 5545, Section 3.3.11 |
| TIME | Current | RFC 5545, Section 3.3.12 |
| UNKNOWN | Reserved - Do not use | RFC 7265, Section 5 |
| URI | Current | RFC 5545, Section 3.3.13 |
| UTC-OFFSET | Current | RFC 5545, Section 3.3.14 |
| XML-REFERENCE | Current | RFC 9253, Section 7 |
| UID | Current | RFC 9253, Section 7 |
Calendar User Types
Registration Procedure(s)
- Expert Review with RFC Required
Expert(s)
- Bernard Desruisseaux, Ken Murchison, Mike Douglass
Reference
- RFC 5545: Internet Calendaring and Scheduling Core Object Specification (iCalendar)
Available Formats
| Calendar User Type | Status | Reference |
|---|---|---|
| INDIVIDUAL | Current | RFC 5545, Section 3.2.3 |
| GROUP | Current | RFC 5545, Section 3.2.3 |
| RESOURCE | Current | RFC 5545, Section 3.2.3 |
| ROOM | Current | RFC 5545, Section 3.2.3 |
| UNKNOWN | Current | RFC 5545, 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
- RFC 5545: Internet Calendaring and Scheduling Core Object Specification (iCalendar)
Available Formats
| Free/Busy Time Type | Status | Reference |
|---|---|---|
| FREE | Current | RFC 5545, Section 3.2.9 |
| BUSY | Current | RFC 5545, Section 3.2.9 |
| BUSY-UNAVAILABLE | Current | RFC 5545, Section 3.2.9 |
| BUSY-TENTATIVE | Current | RFC 5545, Section 3.2.9 |
Participation Statuses
Registration Procedure(s)
- Expert Review with RFC Required
Expert(s)
- Bernard Desruisseaux, Ken Murchison, Mike Douglass
Reference
- RFC 5545: Internet Calendaring and Scheduling Core Object Specification (iCalendar)
Note
A Standards Track RFC is REQUIRED for the registration of Participation Status values to be used in "VEVENT" calendar components.
Available Formats
| Participation Status | Status | Reference |
|---|---|---|
| NEEDS-ACTION | Current | RFC 5545, Section 3.2.12 |
| ACCEPTED | Current | RFC 5545, Section 3.2.12 |
| DECLINED | Current | RFC 5545, Section 3.2.12 |
| TENTATIVE | Current | RFC 5545, Section 3.2.12 |
| DELEGATED | Current | RFC 5545, Section 3.2.12 |
| COMPLETED | Current | RFC 5545, Section 3.2.12 |
| IN-PROCESS | Current | RFC 5545, Section 3.2.12 |
| FAILED | Current | RFC-ietf-calext-ical-tasks-17, Section 9.1 |
Relationship Types
Registration Procedure(s)
- Expert Review with RFC Required
Expert(s)
- Bernard Desruisseaux, Ken Murchison, Mike Douglass
Reference
- RFC 5545: Internet Calendaring and Scheduling Core Object Specification (iCalendar)
Available Formats
| Relationship Type | Status | Reference |
|---|---|---|
| CHILD | Current | RFC 5545, Section 3.2.15 |
| PARENT | Current | RFC 5545, Section 3.2.15 |
| SIBLING | Current | RFC 5545, Section 3.2.15 |
| SNOOZE | Current | RFC 9074, Section 7.1 |
| CONCEPT | Current | RFC 9253, Section 5 |
| DEPENDS-ON | Current | RFC 9253, Section 5 |
| FINISHTOFINISH | Current | RFC 9253, Section 4 |
| FINISHTOSTART | Current | RFC 9253, Section 4 |
| FIRST | Current | RFC 9253, Section 5 |
| NEXT | Current | RFC 9253, Section 5 |
| REFID | Current | RFC 9253, Section 5 |
| STARTTOFINISH | Current | RFC 9253, Section 4 |
| STARTTOSTART | Current | RFC 9253, Section 4 |
Participation Roles
Registration Procedure(s)
- Expert Review with RFC Required
Expert(s)
- Bernard Desruisseaux, Ken Murchison, Mike Douglass
Reference
- RFC 5545: Internet Calendaring and Scheduling Core Object Specification (iCalendar)
Available Formats
| Role Type | Status | Reference |
|---|---|---|
| CHAIR | Current | RFC 5545, Section 3.2.16 |
| REQ-PARTICIPANT | Current | RFC 5545, Section 3.2.16 |
| OPT-PARTICIPANT | Current | RFC 5545, Section 3.2.16 |
| NON-PARTICIPANT | Current | RFC 5545, Section 3.2.16 |
Actions
Registration Procedure(s)
- Expert Review with RFC Required
Expert(s)
- Bernard Desruisseaux, Ken Murchison, Mike Douglass
Reference
- RFC 5545: Internet Calendaring and Scheduling Core Object Specification (iCalendar)
Available Formats
| Action | Status | Reference |
|---|---|---|
| AUDIO | Current | RFC 5545, Section 3.8.6.1 |
| DISPLAY | Current | RFC 5545, Section 3.8.6.1 |
| Current | RFC 5545, Section 3.8.6.1 | |
| PROCEDURE | Deprecated | RFC 2445, Section 4.8.6.1 |
Classifications
Registration Procedure(s)
- Expert Review with RFC Required
Expert(s)
- Bernard Desruisseaux, Ken Murchison, Mike Douglass
Reference
- RFC 5545: Internet Calendaring and Scheduling Core Object Specification (iCalendar)
Available Formats
| Classification | Status | Reference |
|---|---|---|
| PUBLIC | Current | RFC 5545, Section 3.8.1.3 |
| PRIVATE | Current | RFC 5545, Section 3.8.1.3 |
| CONFIDENTIAL | Current | RFC 5545, Section 3.8.1.3 |
Methods
Registration Procedure(s)
- Expert Review with RFC Required
Expert(s)
- Bernard Desruisseaux, Ken Murchison, Mike Douglass
Reference
- RFC 5545: Internet Calendaring and Scheduling Core Object Specification (iCalendar)
Available Formats
REQUEST-STATUS Values
Registration Procedure(s)
- Expert Review with RFC Required
Expert(s)
- Bernard Desruisseaux, Ken Murchison, Mike Douglass
Reference
- RFC 5546: iCalendar Transport-Independent Interoperability Protocol (iTIP)
Available Formats
Schedule Agent Values Registry
Registration Procedure(s)
- Expert Review with RFC Required
Expert(s)
- Unassigned
Reference
- RFC 6638: Scheduling Extensions to CalDAV
Available Formats
| Schedule Agent | Status | Reference |
|---|---|---|
| SERVER | Current | RFC 6638, Section 7.1 |
| CLIENT | Current | RFC 6638, Section 7.1 |
| NONE | Current | RFC 6638, Section 7.1 |
Schedule Force Send Values Registry
Registration Procedure(s)
- Expert Review with RFC Required
Expert(s)
- Unassigned
Reference
- RFC 6638: Scheduling Extensions to CalDAV
Available Formats
| Schedule Force Send | Status | Reference |
|---|---|---|
| REQUEST | Current | RFC 6638, Section 7.2 |
| REPLY | Current | RFC 6638, Section 7.2 |
Display Types
Registration Procedure(s)
- Expert Review with RFC Required
Expert(s)
- Unassigned
Reference
- RFC 7986: New Properties for iCalendar
Available Formats
| Display Type | Status | Reference |
|---|---|---|
| BADGE | Current | RFC 7986, Section 6.1 |
| GRAPHIC | Current | RFC 7986, Section 6.1 |
| FULLSIZE | Current | RFC 7986, Section 6.1 |
| THUMBNAIL | Current | RFC 7986, Section 6.1 |
Feature Types
Registration Procedure(s)
- Expert Review with RFC Required
Expert(s)
- Unassigned
Reference
- RFC 7986: New Properties for iCalendar
Available Formats
| Name | Status | Reference |
|---|---|---|
| AUDIO | Current | RFC 7986, Section 6.3 |
| CHAT | Current | RFC 7986, Section 6.3 |
| FEED | Current | RFC 7986, Section 6.3 |
| MODERATOR | Current | RFC 7986, Section 6.3 |
| PHONE | Current | RFC 7986, Section 6.3 |
| SCREEN | Current | RFC 7986, Section 6.3 |
| VIDEO | Current | RFC 7986, Section 6.3 |
Participant Types
Registration Procedure(s)
- Expert Review
Expert(s)
- Ken Murchison, Michael Douglass
Reference
- RFC 9073: Event Publishing Extensions to iCalendar
Available Formats
| Participant Type | Status | Reference |
|---|---|---|
| ACTIVE | Current | RFC 9073, Section 6.2 |
| INACTIVE | Current | RFC 9073, Section 6.2 |
| SPONSOR | Current | RFC 9073, Section 6.2 |
| CONTACT | Current | RFC 9073, Section 6.2 |
| BOOKING-CONTACT | Current | RFC 9073, Section 6.2 |
| EMERGENCY-CONTACT | Current | RFC 9073, Section 6.2 |
| PUBLICITY-CONTACT | Current | RFC 9073, Section 6.2 |
| PLANNER-CONTACT | Current | RFC 9073, Section 6.2 |
| PERFORMER | Current | RFC 9073, Section 6.2 |
| SPEAKER | Current | RFC 9073, Section 6.2 |
Resource Types
Registration Procedure(s)
- Expert Review
Expert(s)
- Ken Murchison, Michael Douglass
Reference
- RFC 9073: Event Publishing Extensions to iCalendar
Available Formats
| Resource Type | Status | Reference |
|---|---|---|
| PROJECTOR | Current | RFC 9073, Section 6.3 |
| ROOM | Current | RFC 9073, Section 6.3 |
| REMOTE-CONFERENCE-AUDIO | Current | RFC 9073, Section 6.3 |
| REMOTE-CONFERENCE-VIDEO | Current | RFC 9073, Section 6.3 |
Proximity Values
Registration Procedure(s)
- Expert Review with RFC Required
Expert(s)
- Ken Murchison, Michael Douglass
Reference
- RFC 9074: "VALARM" Extensions for iCalendar
Available Formats
| Value | Status | Reference |
|---|---|---|
| ARRIVE | Current | RFC 9074, Section 8.1 |
| DEPART | Current | RFC 9074, Section 8.1 |
| CONNECT | Current | RFC 9074, Section 8.1 |
| DISCONNECT | Current | RFC 9074, Section 8.1 |
STATUS Values
Registration Procedure(s)
- Standards Action With Expert Review
Expert(s)
- Unassigned
Reference
- RFC-ietf-calext-ical-tasks-17: Task Extensions to iCalendar
Available Formats
| Name | Status | Reference |
|---|---|---|
| CANCELLED | Current | RFC 5545, Section 3.8.1.11 |
| COMPLETED | Current | RFC 5545, Section 3.8.1.11 |
| CONFIRMED | Current | RFC 5545, Section 3.8.1.11 |
| DRAFT | Current | RFC 5545, Section 3.8.1.11 |
| FAILED | Current | RFC-ietf-calext-ical-tasks-17, Section 11.2 |
| FINAL | Current | RFC 5545, Section 3.8.1.11 |
| IN-PROCESS | Current | RFC 5545, Section 3.8.1.11 |
| NEEDS-ACTION | Current | RFC 5545, Section 3.8.1.11 |
| PENDING | Current | RFC-ietf-calext-ical-tasks-17, Section 11.2 |
| TENTATIVE | Current | RFC 5545, Section 3.8.1.11 |
SUBSTATE Values
Registration Procedure(s)
- Standards Action With Expert Review
Expert(s)
- Unassigned
Reference
- RFC-ietf-calext-ical-tasks-17: Task Extensions to iCalendar
Available Formats
| Substate | Status | Reference |
|---|---|---|
| OK | Current | RFC-ietf-calext-ical-tasks-17, Section 10.3 |
| ERROR | Current | RFC-ietf-calext-ical-tasks-17, Section 10.3 |
| SUSPENDED | Current | RFC-ietf-calext-ical-tasks-17, Section 10.3 |
TASK-MODE Values
Registration Procedure(s)
- Standards Action With Expert Review
Expert(s)
- Unassigned
Reference
- RFC-ietf-calext-ical-tasks-17: Task Extensions to iCalendar
Available Formats
| Task Mode | Status | Reference |
|---|---|---|
| AUTOMATIC-COMPLETION | Current | RFC-ietf-calext-ical-tasks-17, Section 10.4 |
| AUTOMATIC-FAILURE | Current | RFC-ietf-calext-ical-tasks-17, Section 10.4 |
| AUTOMATIC | Current | RFC-ietf-calext-ical-tasks-17, Section 10.4 |
| CLIENT | Current | RFC-ietf-calext-ical-tasks-17, Section 10.4 |
| SERVER | Current | RFC-ietf-calext-ical-tasks-17, Section 10.4 |