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icalendar/docs/rfc5545/3_2_property_parameters.rst

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3.2. Property Parameters
========================
A property can have attributes with which it is associated. These
"property parameters" contain meta-information about the property or
the property value. Property parameters are provided to specify such
information as the location of an alternate text representation for a
property value, the language of a text property value, the value type
of the property value, and other attributes.
Property parameter values that contain the COLON, SEMICOLON, or COMMA
character separators MUST be specified as quoted-string text values.
Property parameter values MUST NOT contain the DQUOTE character. The
DQUOTE character is used as a delimiter for parameter values that
contain restricted characters or URI text. For example::
DESCRIPTION;ALTREP="cid:part1.0001@example.org":The Fall'98 Wild
Wizards Conference - - Las Vegas\, NV\, USA
Property parameter values that are not in quoted-strings are case-
insensitive.
The general property parameters defined by this memo are defined by
the following notation::
icalparameter = altrepparam ; Alternate text representation
/ cnparam ; Common name
/ cutypeparam ; Calendar user type
/ delfromparam ; Delegator
/ deltoparam ; Delegatee
/ dirparam ; Directory entry
/ encodingparam ; Inline encoding
/ fmttypeparam ; Format type
/ fbtypeparam ; Free/busy time type
/ languageparam ; Language for text
/ memberparam ; Group or list membership
/ partstatparam ; Participation status
/ rangeparam ; Recurrence identifier range
/ trigrelparam ; Alarm trigger relationship
/ reltypeparam ; Relationship type
/ roleparam ; Participation role
/ rsvpparam ; RSVP expectation
/ sentbyparam ; Sent by
/ tzidparam ; Reference to time zone object
/ valuetypeparam ; Property value data type
/ other-param
other-param = (iana-param / x-param)
iana-param = iana-token "=" param-value *("," param-value)
; Some other IANA-registered iCalendar parameter.
x-param = x-name "=" param-value *("," param-value)
; A non-standard, experimental parameter.
Applications MUST ignore x-param and iana-param values they don't
recognize.
3.2.1 Alternate Text Representation
-----------------------------------
**Parameter Name:** ALTREP
**Purpose:** To specify an alternate text representation for the
property value.
**Format Definition:** This property parameter is defined by the
following notation::
altrepparam = "ALTREP" "=" DQUOTE uri DQUOTE
**Description**: This parameter specifies a URI that points to an
alternate representation for a textual property value. A property
specifying this parameter MUST also include a value that reflects
the default representation of the text value. The URI parameter
value MUST be specified in a quoted-string.
.. note::
While there is no restriction imposed on the URI schemes
allowed for this parameter, Content Identifier (CID) [RFC2392],
HTTP [RFC2616], and HTTPS [RFC2818] are the URI schemes most
commonly used by current implementations.
**Example:**
::
DESCRIPTION;ALTREP="CID:part3.msg.970415T083000@example.com":
Project XYZ Review Meeting will include the following agenda
items: (a) Market Overview\, (b) Finances\, (c) Project Man
agement
The "ALTREP" property parameter value might point to a "text/html"
content portion.
::
Content-Type:text/html
Content-Id:<part3.msg.970415T083000@example.com>
<html>
<head>
<title></title>
</head>
<body>
<p>
<b>Project XYZ Review Meeting</b> will include
the following agenda items:
<ol>
<li>Market Overview</li>
<li>Finances</li>
<li>Project Management</li>
</ol>
</p>
</body>
</html>
3.2.2. Common Name
------------------
**Parameter Name:** CN
**Purpose:** To specify the common name to be associated with the
calendar user specified by the property.
**Format Definition:** This property parameter is defined by the
following notation::
cnparam = "CN" "=" param-value
**Description:** This parameter can be specified on properties with a
CAL-ADDRESS value type. The parameter specifies the common name
to be associated with the calendar user specified by the property.
The parameter value is text. The parameter value can be used for
display text to be associated with the calendar address specified
by the property.
**Example:**
::
ORGANIZER;CN="John Smith":mailto:jsmith@example.com
3.2.3. Calendar User Type
-------------------------
**Parameter Name:** CUTYPE
**Purpose:** To identify the type of calendar user specified by the
property.
**Format Definition:** This property parameter is defined by the
following notation::
::
cutypeparam = "CUTYPE" "="
("INDIVIDUAL" ; An individual
/ "GROUP" ; A group of individuals
/ "RESOURCE" ; A physical resource
/ "ROOM" ; A room resource
/ "UNKNOWN" ; Otherwise not known
/ x-name ; Experimental type
/ iana-token) ; Other IANA-registered
; type
; Default is INDIVIDUAL
**Description:** This parameter can be specified on properties with a
CAL-ADDRESS value type. The parameter identifies the type of
calendar user specified by the property. If not specified on a
property that allows this parameter, the default is INDIVIDUAL.
Applications MUST treat x-name and iana-token values they don't
recognize the same way as they would the UNKNOWN value.
**Example:**
::
ATTENDEE;CUTYPE=GROUP:mailto:ietf-calsch@example.org
3.2.4. Delegators
-----------------
**Parameter Name:** DELEGATED-FROM
**Purpose:** To specify the calendar users that have delegated their
participation to the calendar user specified by the property.
**Format Definition:** This property parameter is defined by the
following notation::
delfromparam = "DELEGATED-FROM" "=" DQUOTE cal-address
DQUOTE *("," DQUOTE cal-address DQUOTE)
**Description:** This parameter can be specified on properties with a
CAL-ADDRESS value type. This parameter specifies those calendar
users that have delegated their participation in a group-scheduled
event or to-do to the calendar user specified by the property.
The individual calendar address parameter values MUST each be
specified in a quoted-string.
**Example:**
::
ATTENDEE;DELEGATED-FROM="mailto:jsmith@example.com":mailto:
jdoe@example.com
3.2.5. Delegatees
-----------------
Parameter Name: DELEGATED-TO
Purpose: To specify the calendar users to whom the calendar user
specified by the property has delegated participation.
Format Definition: This property parameter is defined by the
following notation:
deltoparam = "DELEGATED-TO" "=" DQUOTE cal-address DQUOTE
*("," DQUOTE cal-address DQUOTE)
Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. This parameter specifies those calendar
users whom have been delegated participation in a group-scheduled
event or to-do by the calendar user specified by the property.
The individual calendar address parameter values MUST each be
specified in a quoted-string.
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Example:
ATTENDEE;DELEGATED-TO="mailto:jdoe@example.com","mailto:jqpublic
@example.com":mailto:jsmith@example.com
3.2.6. Directory Entry Reference
Parameter Name: DIR
Purpose: To specify reference to a directory entry associated with
the calendar user specified by the property.
Format Definition: This property parameter is defined by the
following notation:
dirparam = "DIR" "=" DQUOTE uri DQUOTE
Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. The parameter specifies a reference to
the directory entry associated with the calendar user specified by
the property. The parameter value is a URI. The URI parameter
value MUST be specified in a quoted-string.
Note: While there is no restriction imposed on the URI schemes
allowed for this parameter, CID [RFC2392], DATA [RFC2397], FILE
[RFC1738], FTP [RFC1738], HTTP [RFC2616], HTTPS [RFC2818], LDAP
[RFC4516], and MID [RFC2392] are the URI schemes most commonly
used by current implementations.
Example:
ORGANIZER;DIR="ldap://example.com:6666/o=ABC%20Industries,
c=US???(cn=Jim%20Dolittle)":mailto:jimdo@example.com
3.2.7. Inline Encoding
Parameter Name: ENCODING
Purpose: To specify an alternate inline encoding for the property
value.
Format Definition: This property parameter is defined by the
following notation:
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encodingparam = "ENCODING" "="
( "8BIT"
; "8bit" text encoding is defined in [RFC2045]
/ "BASE64"
; "BASE64" binary encoding format is defined in [RFC4648]
)
Description: This property parameter identifies the inline encoding
used in a property value. The default encoding is "8BIT",
corresponding to a property value consisting of text. The
"BASE64" encoding type corresponds to a property value encoded
using the "BASE64" encoding defined in [RFC2045].
If the value type parameter is ";VALUE=BINARY", then the inline
encoding parameter MUST be specified with the value
";ENCODING=BASE64".
Example:
ATTACH;FMTTYPE=text/plain;ENCODING=BASE64;VALUE=BINARY:TG9yZW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3.2.8. Format Type
Parameter Name: FMTTYPE
Purpose: To specify the content type of a referenced object.
Format Definition: This property parameter is defined by the
following notation:
fmttypeparam = "FMTTYPE" "=" type-name "/" subtype-name
; Where "type-name" and "subtype-name" are
; defined in Section 4.2 of [RFC4288].
Description: This parameter can be specified on properties that are
used to reference an object. The parameter specifies the media
type [RFC4288] of the referenced object. For example, on the
"ATTACH" property, an FTP type URI value does not, by itself,
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RFC 5545 iCalendar September 2009
necessarily convey the type of content associated with the
resource. The parameter value MUST be the text for either an
IANA-registered media type or a non-standard media type.
Example:
ATTACH;FMTTYPE=application/msword:ftp://example.com/pub/docs/
agenda.doc
3.2.9. Free/Busy Time Type
Parameter Name: FBTYPE
Purpose: To specify the free or busy time type.
Format Definition: This property parameter is defined by the
following notation:
fbtypeparam = "FBTYPE" "=" ("FREE" / "BUSY"
/ "BUSY-UNAVAILABLE" / "BUSY-TENTATIVE"
/ x-name
; Some experimental iCalendar free/busy type.
/ iana-token)
; Some other IANA-registered iCalendar free/busy type.
Description: This parameter specifies the free or busy time type.
The value FREE indicates that the time interval is free for
scheduling. The value BUSY indicates that the time interval is
busy because one or more events have been scheduled for that
interval. The value BUSY-UNAVAILABLE indicates that the time
interval is busy and that the interval can not be scheduled. The
value BUSY-TENTATIVE indicates that the time interval is busy
because one or more events have been tentatively scheduled for
that interval. If not specified on a property that allows this
parameter, the default is BUSY. Applications MUST treat x-name
and iana-token values they don't recognize the same way as they
would the BUSY value.
Example: The following is an example of this parameter on a
"FREEBUSY" property.
FREEBUSY;FBTYPE=BUSY:19980415T133000Z/19980415T170000Z
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3.2.10. Language
Parameter Name: LANGUAGE
Purpose: To specify the language for text values in a property or
property parameter.
Format Definition: This property parameter is defined by the
following notation:
languageparam = "LANGUAGE" "=" language
language = Language-Tag
; As defined in [RFC5646].
Description: This parameter identifies the language of the text in
the property value and of all property parameter values of the
property. The value of the "LANGUAGE" property parameter is that
defined in [RFC5646].
For transport in a MIME entity, the Content-Language header field
can be used to set the default language for the entire body part.
Otherwise, no default language is assumed.
Example: The following are examples of this parameter on the
"SUMMARY" and "LOCATION" properties:
SUMMARY;LANGUAGE=en-US:Company Holiday Party
LOCATION;LANGUAGE=en:Germany
LOCATION;LANGUAGE=no:Tyskland
3.2.11. Group or List Membership
Parameter Name: MEMBER
Purpose: To specify the group or list membership of the calendar
user specified by the property.
Format Definition: This property parameter is defined by the
following notation:
memberparam = "MEMBER" "=" DQUOTE cal-address DQUOTE
*("," DQUOTE cal-address DQUOTE)
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Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. The parameter identifies the groups or
list membership for the calendar user specified by the property.
The parameter value is either a single calendar address in a
quoted-string or a COMMA-separated list of calendar addresses,
each in a quoted-string. The individual calendar address
parameter values MUST each be specified in a quoted-string.
Example:
ATTENDEE;MEMBER="mailto:ietf-calsch@example.org":mailto:
jsmith@example.com
ATTENDEE;MEMBER="mailto:projectA@example.com","mailto:pr
ojectB@example.com":mailto:janedoe@example.com
3.2.12. Participation Status
Parameter Name: PARTSTAT
Purpose: To specify the participation status for the calendar user
specified by the property.
Format Definition: This property parameter is defined by the
following notation:
partstatparam = "PARTSTAT" "="
(partstat-event
/ partstat-todo
/ partstat-jour)
partstat-event = ("NEEDS-ACTION" ; Event needs action
/ "ACCEPTED" ; Event accepted
/ "DECLINED" ; Event declined
/ "TENTATIVE" ; Event tentatively
; accepted
/ "DELEGATED" ; Event delegated
/ x-name ; Experimental status
/ iana-token) ; Other IANA-registered
; status
; These are the participation statuses for a "VEVENT".
; Default is NEEDS-ACTION.
partstat-todo = ("NEEDS-ACTION" ; To-do needs action
/ "ACCEPTED" ; To-do accepted
/ "DECLINED" ; To-do declined
/ "TENTATIVE" ; To-do tentatively
; accepted
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RFC 5545 iCalendar September 2009
/ "DELEGATED" ; To-do delegated
/ "COMPLETED" ; To-do completed
; COMPLETED property has
; DATE-TIME completed
/ "IN-PROCESS" ; To-do in process of
; being completed
/ x-name ; Experimental status
/ iana-token) ; Other IANA-registered
; status
; These are the participation statuses for a "VTODO".
; Default is NEEDS-ACTION.
partstat-jour = ("NEEDS-ACTION" ; Journal needs action
/ "ACCEPTED" ; Journal accepted
/ "DECLINED" ; Journal declined
/ x-name ; Experimental status
/ iana-token) ; Other IANA-registered
; status
; These are the participation statuses for a "VJOURNAL".
; Default is NEEDS-ACTION.
Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. The parameter identifies the
participation status for the calendar user specified by the
property value. The parameter values differ depending on whether
they are associated with a group-scheduled "VEVENT", "VTODO", or
"VJOURNAL". The values MUST match one of the values allowed for
the given calendar component. If not specified on a property that
allows this parameter, the default value is NEEDS-ACTION.
Applications MUST treat x-name and iana-token values they don't
recognize the same way as they would the NEEDS-ACTION value.
Example:
ATTENDEE;PARTSTAT=DECLINED:mailto:jsmith@example.com
3.2.13. Recurrence Identifier Range
Parameter Name: RANGE
Purpose: To specify the effective range of recurrence instances from
the instance specified by the recurrence identifier specified by
the property.
Format Definition: This property parameter is defined by the
following notation:
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RFC 5545 iCalendar September 2009
rangeparam = "RANGE" "=" "THISANDFUTURE"
; To specify the instance specified by the recurrence identifier
; and all subsequent recurrence instances.
Description: This parameter can be specified on a property that
specifies a recurrence identifier. The parameter specifies the
effective range of recurrence instances that is specified by the
property. The effective range is from the recurrence identifier
specified by the property. If this parameter is not specified on
an allowed property, then the default range is the single instance
specified by the recurrence identifier value of the property. The
parameter value can only be "THISANDFUTURE" to indicate a range
defined by the recurrence identifier and all subsequent instances.
The value "THISANDPRIOR" is deprecated by this revision of
iCalendar and MUST NOT be generated by applications.
Example:
RECURRENCE-ID;RANGE=THISANDFUTURE:19980401T133000Z
3.2.14. Alarm Trigger Relationship
Parameter Name: RELATED
Purpose: To specify the relationship of the alarm trigger with
respect to the start or end of the calendar component.
Format Definition: This property parameter is defined by the
following notation:
trigrelparam = "RELATED" "="
("START" ; Trigger off of start
/ "END") ; Trigger off of end
Description: This parameter can be specified on properties that
specify an alarm trigger with a "DURATION" value type. The
parameter specifies whether the alarm will trigger relative to the
start or end of the calendar component. The parameter value START
will set the alarm to trigger off the start of the calendar
component; the parameter value END will set the alarm to trigger
off the end of the calendar component. If the parameter is not
specified on an allowable property, then the default is START.
Example:
TRIGGER;RELATED=END:PT5M
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3.2.15. Relationship Type
Parameter Name: RELTYPE
Purpose: To specify the type of hierarchical relationship associated
with the calendar component specified by the property.
Format Definition: This property parameter is defined by the
following notation:
reltypeparam = "RELTYPE" "="
("PARENT" ; Parent relationship - Default
/ "CHILD" ; Child relationship
/ "SIBLING" ; Sibling relationship
/ iana-token ; Some other IANA-registered
; iCalendar relationship type
/ x-name) ; A non-standard, experimental
; relationship type
Description: This parameter can be specified on a property that
references another related calendar. The parameter specifies the
hierarchical relationship type of the calendar component
referenced by the property. The parameter value can be PARENT, to
indicate that the referenced calendar component is a superior of
calendar component; CHILD to indicate that the referenced calendar
component is a subordinate of the calendar component; or SIBLING
to indicate that the referenced calendar component is a peer of
the calendar component. If this parameter is not specified on an
allowable property, the default relationship type is PARENT.
Applications MUST treat x-name and iana-token values they don't
recognize the same way as they would the PARENT value.
Example:
RELATED-TO;RELTYPE=SIBLING:19960401-080045-4000F192713@
example.com
3.2.16. Participation Role
Parameter Name: ROLE
Purpose: To specify the participation role for the calendar user
specified by the property.
Format Definition: This property parameter is defined by the
following notation:
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RFC 5545 iCalendar September 2009
roleparam = "ROLE" "="
("CHAIR" ; Indicates chair of the
; calendar entity
/ "REQ-PARTICIPANT" ; Indicates a participant whose
; participation is required
/ "OPT-PARTICIPANT" ; Indicates a participant whose
; participation is optional
/ "NON-PARTICIPANT" ; Indicates a participant who
; is copied for information
; purposes only
/ x-name ; Experimental role
/ iana-token) ; Other IANA role
; Default is REQ-PARTICIPANT
Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. The parameter specifies the participation
role for the calendar user specified by the property in the group
schedule calendar component. If not specified on a property that
allows this parameter, the default value is REQ-PARTICIPANT.
Applications MUST treat x-name and iana-token values they don't
recognize the same way as they would the REQ-PARTICIPANT value.
Example:
ATTENDEE;ROLE=CHAIR:mailto:mrbig@example.com
3.2.17. RSVP Expectation
Parameter Name: RSVP
Purpose: To specify whether there is an expectation of a favor of a
reply from the calendar user specified by the property value.
Format Definition: This property parameter is defined by the
following notation:
rsvpparam = "RSVP" "=" ("TRUE" / "FALSE")
; Default is FALSE
Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. The parameter identifies the expectation
of a reply from the calendar user specified by the property value.
This parameter is used by the "Organizer" to request a
participation status reply from an "Attendee" of a group-scheduled
event or to-do. If not specified on a property that allows this
parameter, the default value is FALSE.
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Example:
ATTENDEE;RSVP=TRUE:mailto:jsmith@example.com
3.2.18. Sent By
Parameter Name: SENT-BY
Purpose: To specify the calendar user that is acting on behalf of
the calendar user specified by the property.
Format Definition: This property parameter is defined by the
following notation:
sentbyparam = "SENT-BY" "=" DQUOTE cal-address DQUOTE
Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. The parameter specifies the calendar user
that is acting on behalf of the calendar user specified by the
property. The parameter value MUST be a mailto URI as defined in
[RFC2368]. The individual calendar address parameter values MUST
each be specified in a quoted-string.
Example:
ORGANIZER;SENT-BY="mailto:sray@example.com":mailto:
jsmith@example.com
3.2.19. Time Zone Identifier
Parameter Name: TZID
Purpose: To specify the identifier for the time zone definition for
a time component in the property value.
Format Definition: This property parameter is defined by the
following notation:
tzidparam = "TZID" "=" [tzidprefix] paramtext
tzidprefix = "/"
Description: This parameter MUST be specified on the "DTSTART",
"DTEND", "DUE", "EXDATE", and "RDATE" properties when either a
DATE-TIME or TIME value type is specified and when the value is
neither a UTC or a "floating" time. Refer to the DATE-TIME or
TIME value type definition for a description of UTC and "floating
time" formats. This property parameter specifies a text value
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that uniquely identifies the "VTIMEZONE" calendar component to be
used when evaluating the time portion of the property. The value
of the "TZID" property parameter will be equal to the value of the
"TZID" property for the matching time zone definition. An
individual "VTIMEZONE" calendar component MUST be specified for
each unique "TZID" parameter value specified in the iCalendar
object.
The parameter MUST be specified on properties with a DATE-TIME
value if the DATE-TIME is not either a UTC or a "floating" time.
Failure to include and follow VTIMEZONE definitions in iCalendar
objects may lead to inconsistent understanding of the local time
at any given location.
The presence of the SOLIDUS character as a prefix, indicates that
this "TZID" represents a unique ID in a globally defined time zone
registry (when such registry is defined).
Note: This document does not define a naming convention for
time zone identifiers. Implementers may want to use the naming
conventions defined in existing time zone specifications such
as the public-domain TZ database [TZDB]. The specification of
globally unique time zone identifiers is not addressed by this
document and is left for future study.
The following are examples of this property parameter:
DTSTART;TZID=America/New_York:19980119T020000
DTEND;TZID=America/New_York:19980119T030000
The "TZID" property parameter MUST NOT be applied to DATE
properties and DATE-TIME or TIME properties whose time values are
specified in UTC.
The use of local time in a DATE-TIME or TIME value without the
"TZID" property parameter is to be interpreted as floating time,
regardless of the existence of "VTIMEZONE" calendar components in
the iCalendar object.
For more information, see the sections on the value types DATE-
TIME and TIME.
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3.2.20. Value Data Types
Parameter Name: VALUE
Purpose: To explicitly specify the value type format for a property
value.
Format Definition: This property parameter is defined by the
following notation:
valuetypeparam = "VALUE" "=" valuetype
valuetype = ("BINARY"
/ "BOOLEAN"
/ "CAL-ADDRESS"
/ "DATE"
/ "DATE-TIME"
/ "DURATION"
/ "FLOAT"
/ "INTEGER"
/ "PERIOD"
/ "RECUR"
/ "TEXT"
/ "TIME"
/ "URI"
/ "UTC-OFFSET"
/ x-name
; Some experimental iCalendar value type.
/ iana-token)
; Some other IANA-registered iCalendar value type.
Description: This parameter specifies the value type and format of
the property value. The property values MUST be of a single value
type. For example, a "RDATE" property cannot have a combination
of DATE-TIME and TIME value types.
If the property's value is the default value type, then this
parameter need not be specified. However, if the property's
default value type is overridden by some other allowable value
type, then this parameter MUST be specified.
Applications MUST preserve the value data for x-name and iana-
token values that they don't recognize without attempting to
interpret or parse the value data.
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