iCalendar Element Registries
 Created
 20090429
 Last Updated
 20230221
 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
 Properties
 Parameters
 Value Data Types
 Calendar User Types
 Free/Busy Time Types
 Participation Statuses
 Relationship Types
 Participation Roles
 Actions
 Classifications
 Methods
 REQUESTSTATUS Values
 Schedule Agent Values Registry
 Schedule Force Send Values Registry
 Display Types
 Feature Types
 Participant Types
 Resource Types
 Proximity Values
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 
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 
PERCENTCOMPLETE  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 
RECURRENCEID  Current  [RFC5545], Section 3.8.4.4 
RELATEDTO  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 
LASTMODIFIED  Current  [RFC5545], Section 3.8.7.3; [RFC7986], Section 5.4 
SEQUENCE  Current  [RFC5545], Section 3.8.7.4 
REQUESTSTATUS  Current  [RFC5545], Section 3.8.8.3 
XML  Current  [RFC6321], Section 4.2 
TZUNTIL  Current  [RFC7808], Section 7.1 
TZIDALIASOF  Current  [RFC7808], Section 7.2 
BUSYTYPE  Current  [RFC7953], Section 3.2 
NAME  Current  [RFC7986], Section 5.1 
REFRESHINTERVAL  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 
CALENDARADDRESS  Current  [RFC9073], Section 6.4 
LOCATIONTYPE  Current  [RFC9073], Section 6.1 
PARTICIPANTTYPE  Current  [RFC9073], Section 6.2 
RESOURCETYPE  Current  [RFC9073], Section 6.3 
STRUCTUREDDATA  Current  [RFC9073], Section 6.6 
STYLEDDESCRIPTION  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 
DELEGATEDFROM  Current  [RFC5545], Section 3.2.4 
DELEGATEDTO  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 
SCHEDULEAGENT  Current  [RFC6638], Section 7.1 
SCHEDULEFORCESEND  Current  [RFC6638], Section 7.2 
SCHEDULESTATUS  Current  [RFC6638], Section 7.3 
SENTBY  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 
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 
MANAGEDID  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 
CALADDRESS  Current  [RFC5545], Section 3.3.3 
DATE  Current  [RFC5545], Section 3.3.4 
DATETIME  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 
UTCOFFSET  Current  [RFC5545], Section 3.3.14 
XMLREFERENCE  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 
BUSYUNAVAILABLE  Current  [RFC5545], Section 3.2.9 
BUSYTENTATIVE  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 

NEEDSACTION  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 
INPROCESS  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 
DEPENDSON  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 
REQPARTICIPANT  Current  [RFC5545], Section 3.2.16 
OPTPARTICIPANT  Current  [RFC5545], Section 3.2.16 
NONPARTICIPANT  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 
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] 
REQUESTSTATUS 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 
BOOKINGCONTACT  Current  [RFC9073], Section 6.2 
EMERGENCYCONTACT  Current  [RFC9073], Section 6.2 
PUBLICITYCONTACT  Current  [RFC9073], Section 6.2 
PLANNERCONTACT  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 
REMOTECONFERENCEAUDIO  Current  [RFC9073], Section 6.3 
REMOTECONFERENCEVIDEO  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 