vCard Format Specification

Introduction Electronic address books have become ubiquitous. Their increased presence on portable, connected devices as well as the diversity of platforms that exchange contact data call for a standard. This memo defines the vCard format, which allows the capture and exchange of information normally stored within an address book or directory application. A high-level overview of the differences from RFCs 2425 and 2426 can be found in Appendix A.

Conventions The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in .

vCard Format Specification The text/vcard MIME content type (hereafter known as "vCard"; see ) contains contact information, typically pertaining to a single contact or group of contacts. The content consists of one or more lines in the format given below.

Charset The charset (see for internationalization terminology) for vCard is UTF-8 as defined in . There is no way to override this. It is invalid to specify a value other than "UTF-8" in the "charset" MIME parameter (see ).

Line Delimiting and Folding Individual lines within vCard are delimited by the line break, which is a CRLF sequence (U+000D followed by U+000A). Long logical lines of text can be split into a multiple-physical-line representation using the following folding technique. Content lines SHOULD be folded to a maximum width of 75 octets, excluding the line break. Multi-octet characters MUST remain contiguous. The rationale for this folding process can be found in , Section 2.1.1. A logical line MAY be continued on the next physical line anywhere between two characters by inserting a CRLF immediately followed by a single white space character (space (U+0020) or horizontal tab (U+0009)). The folded line MUST contain at least one character. Any sequence of CRLF followed immediately by a single white space character is ignored (removed) when processing the content type. For example, the line:

can be represented as:

It could also be represented as:

The process of moving from this folded multiple-line representation of a property definition to its single-line representation is called unfolding. Unfolding is accomplished by regarding CRLF immediately followed by a white space character (namely, HTAB (U+0009) or SPACE (U+0020)) as equivalent to no characters at all (i.e., the CRLF and single white space character are removed). Note: It is possible for very simple implementations to generate improperly folded lines in the middle of a UTF-8 multi-octet sequence. For this reason, implementations SHOULD unfold lines in such a way as to properly restore the original sequence. Note: Unfolding is done differently than in . Unfolding in only removes the CRLF, not the space following it. Folding is done after any content encoding of a type value. Unfolding is done before any decoding of a type value in a content line.

ABNF Format Definition The following ABNF uses the notation of , which also defines CRLF, WSP, DQUOTE, VCHAR, ALPHA, and DIGIT.

A line that begins with a white space character is a continuation of the previous line, as described in . The white space character and immediately preceeding CRLF should be discarded when reconstructing the original line. Note that this line-folding convention differs from that found in , in that the sequence <CRLF><WSP> found anywhere in the content indicates a continued line and should be removed. Property names and parameter names are case-insensitive (e.g., the property name "fn" is the same as "FN" and "Fn"). Parameter values MAY be case-sensitive or case-insensitive, depending on their definition. Parameter values that are not explicitly defined as being case-sensitive are case-insensitive. Based on experience with vCard 3 interoperability, it is RECOMMENDED that property and parameter names be upper-case on output. The group construct is used to group related properties together. The group name is a syntactic convention used to indicate that all property names prefaced with the same group name SHOULD be grouped together when displayed by an application. It has no other significance. Implementations that do not understand or support grouping MAY simply strip off any text before a "." to the left of the type name and present the types and values as normal. Property cardinalities are indicated using the following notation, which is based on ABNF (see , Section 3.6): Cardinality Meaning 1 Exactly one instance per vCard MUST be present. *1 Exactly one instance per vCard MAY be present. 1* One or more instances per vCard MUST be present. * One or more instances per vCard MAY be present. Properties defined in a vCard instance may have multiple values depending on the property cardinality. The general rule for encoding multi-valued properties is to simply create a new content line for each value (including the property name). However, it should be noted that some value types support encoding multiple values in a single content line by separating the values with a comma ",". This approach has been taken for several of the content types defined below (date, time, integer, float). A property whose value is structured, such as ADR or ORG, MUST NOT combine multiple instances on a single content line; each instance is placed on its own line.

Property Value Escaping Within a property value, certain characters are escaped using a BACKSLASH character (U+005C). A COMMA (U+002C) or a SEMICOLON (U+003B) is escaped by preceding it with a BACKSLASH, so that it is not taken for a separator; a literal BACKSLASH is written as two BACKSLASH characters; and a NEWLINE (U+000A) is encoded as a BACKSLASH followed by an 'n' (U+006E) or an 'N' (U+004E). Which of these characters must be escaped depends on the value's type. A "text" value MUST escape any COMMA it contains, even for a property that does not allow multiple values (for consistency), and MUST escape any BACKSLASH or NEWLINE. It MAY escape a SEMICOLON but need not, because within a "text" value a SEMICOLON is ordinary content rather than a separator. A "component" value -- the building block of structured properties like those of N, ADR, and ORG values -- MUST escape any COMMA, SEMICOLON, BACKSLASH, or NEWLINE it contains, even where the structure does not allow multiple values (for consistency). Outside of "text" and "component" values, none of these characters is escaped. Most value types cannot contain any of them, and although a "uri" value may contain a COMMA or a SEMICOLON (), a URI is never in a list or component list. For tolerance of vCards produced under earlier specifications, a parser MAY accept a backslash-escaped COMMA or SEMICOLON within a "uri" value as the literal character. A few properties define a structured value as a fixed sequence of fields rather than from "component" values; CLIENTPIDMAP and GENDER are examples in this document. In each, the field preceding the semicolon cannot itself contain a semicolon, so the grammar locates the separator unambiguously; the semicolon is not escaped, and each field is interpreted according to its own type. In all other cases, escaping MUST NOT be used.

Property Value Data Types Standard value types are defined below.

iana-valuespec = ; a publicly defined valuetype format, registered ; with IANA, as defined in Section 10.2.5 of this ; document. ]]>

TEXT "text": The "text" value type should be used to identify values that contain human-readable text. As for the language, it is controlled by the LANGUAGE property parameter defined in . Examples for "text":

A formatted text line break in a text value type MUST be represented as the character sequence backslash (U+005C) followed by a Latin small letter n (U+006E) or a Latin capital letter N (U+004E), that is, "\n" or "\N". For example, a multiple line NOTE value of:

could be represented as:

demonstrating the \n literal formatted line break technique, the CRLF-followed-by-space line folding technique, and the backslash escape technique.

URI "uri": The "uri" value type should be used to identify values that are referenced by a Uniform Resource Identifier (URI) instead of encoded in-line. These value references might be used if the value is too large, or otherwise undesirable to include directly. The format for the URI is as defined in Section 3 of . Note that the value of a property of type "uri" is what the URI points to, not the URI itself. Examples for "uri":

DATE, TIME, DATE-TIME, DATE-AND-OR-TIME, and TIMESTAMP "date", "time", "date-time", "date-and-or-time", and "timestamp": Each of these value types is based on the definitions in . Multiple such values can be specified using the comma-separated notation. Only the basic format is supported.

DATE A calendar date as specified in , Section 4.1.2. Reduced accuracy, as specified in , Sections 4.1.2.3 a) and b), but not c), is permitted. Expanded representation, as specified in , Section 4.1.4, is forbidden. Truncated representation, as specified in , Sections 5.2.1.3 d), e), and f), is permitted. Examples for "date":

Note the use of YYYY-MM in the second example above. YYYYMM is disallowed to prevent confusion with YYMMDD. Note also that YYYY-MM-DD is disallowed since we are using the basic format instead of the extended format.

TIME A time of day as specified in , Section 4.2. Reduced accuracy, as specified in , Section 4.2.2.3, is permitted. Representation with decimal fraction, as specified in , Section 4.2.2.4, is forbidden. The midnight hour is always represented by 00, never 24 (see , Section 4.2.3). Truncated representation, as specified in , Sections 5.3.1.4 a), b), and c), is permitted. Examples for "time":

DATE-TIME A date and time of day combination as specified in , Section 4.3. Truncation of the date part, as specified in , Section 5.4.2 c), is permitted. Examples for "date-time":

DATE-AND-OR-TIME Either a DATE-TIME, a DATE, or a TIME value. To allow unambiguous interpretation, a stand-alone TIME value is always preceded by a "T". Examples for "date-and-or-time":

TIMESTAMP A complete date and time of day combination as specified in , Section 4.3.2. Examples for "timestamp":

BOOLEAN "boolean": The "boolean" value type is used to express boolean values. These values are case-insensitive. Examples:

INTEGER "integer": The "integer" value type is used to express signed integers in decimal format. If sign is not specified, the value is assumed positive "+". Multiple "integer" values can be specified using the comma-separated notation. The maximum value is 9223372036854775807, and the minimum value is -9223372036854775808. These limits correspond to a signed 64-bit integer using two's- complement arithmetic. Examples:

FLOAT "float": The "float" value type is used to express real numbers. If sign is not specified, the value is assumed positive "+". Multiple "float" values can be specified using the comma-separated notation. Implementations MUST support a precision equal or better than that of the IEEE "binary64" format . Note: Scientific notation is disallowed. Implementers wishing to use their favorite language's %f formatting should be careful. Examples:

UTC-OFFSET "utc-offset": The "utc-offset" value type specifies that the property value is a signed offset from UTC. This value type can be specified in the TZ property. The value type is an offset from Coordinated Universal Time (UTC). It is specified as a positive or negative difference in units of hours and minutes (e.g., +hhmm). The time is specified as a 24-hour clock. Hour values are from 00 to 23, and minute values are from 00 to 59. Hour and minutes are 2 digits with high-order zeroes required to maintain digit count. The basic format for ISO 8601 UTC offsets MUST be used.

LANGUAGE-TAG "language-tag": A single language tag, as defined in .

Property Parameters A property can have attributes associated with it. These "property parameters" contain meta-information about the property or the property value. In some cases, the property parameter can be multi- valued in which case the property parameter value elements are separated by a COMMA (U+002C). Property parameter value elements that contain the COLON (U+003A), SEMICOLON (U+003B), or COMMA (U+002C) character separators MUST be specified as quoted-string text values. Property parameter values MUST NOT contain the DQUOTE (U+0022) character. The DQUOTE character is used as a delimiter for parameter values that contain restricted characters or URI text. Applications MUST ignore x-param and iana-param values they don't recognize.

LANGUAGE The LANGUAGE property parameter is used to identify data in multiple languages. There is no concept of "default" language, except as specified by any "Content-Language" MIME header parameter that is present . The value of the LANGUAGE property parameter is a language tag as defined in Section 2 of . Examples:

ABNF:

VALUE The VALUE parameter is OPTIONAL, used to identify the value type (data type) and format of the value. The use of these predefined formats is encouraged even if the value parameter is not explicitly used. By defining a standard set of value types and their formats, existing parsing and processing code can be leveraged. The predefined data type values MUST NOT be repeated in COMMA-separated value lists except within the N, NICKNAME, ADR, and CATEGORIES properties. Although the VALUE parameter is OPTIONAL, a property defined outside this document whose default value type is not "text" SHOULD nonetheless include it on each instance, stating the type explicitly. A consumer that does not recognize a property cannot determine its value type from the property name alone, and so may mishandle a non-text value -- for example, treating a COMMA within a URI value as a value separator. See for the matching registration guidance. ABNF:

PREF The PREF parameter is OPTIONAL and is used to indicate that the corresponding instance of a property is preferred by the vCard author. Its value MUST be an integer between 1 and 100 that quantifies the level of preference. Lower values correspond to a higher level of preference, with 1 being most preferred. When the parameter is absent, the default MUST be to interpret the property instance as being least preferred. Note that the value of this parameter is to be interpreted only in relation to values assigned to other instances of the same property in the same vCard. A given value, or the absence of a value, MUST NOT be interpreted on its own. This parameter MAY be applied to any property that allows multiple instances. ABNF:

ALTID The ALTID parameter is used to "tag" property instances as being alternative representations of the same logical property. For example, translations of a property in multiple languages generates multiple property instances having different LANGUAGE () parameter that are tagged with the same ALTID value. This parameter's value is treated as an opaque string. Its sole purpose is to be compared for equality against other ALTID parameter values. Two property instances are considered alternative representations of the same logical property if and only if their names as well as the value of their ALTID parameters are identical. Property instances without the ALTID parameter MUST NOT be considered an alternative representation of any other property instance. Values for the ALTID parameter are not globally unique: they MAY be reused for different property names. Property instances having the same ALTID parameter value count as 1 toward cardinality. Therefore, since N () has cardinality *1 and TITLE () has cardinality *, these three examples would be legal:

;;;; N;ALTID=1;LANGUAGE=en:Yamada;Taro;;; ( denotes a UTF8-encoded Unicode character.) TITLE;ALTID=1;LANGUAGE=fr:Patron TITLE;ALTID=1;LANGUAGE=en:Boss TITLE;ALTID=1;LANGUAGE=fr:Patron TITLE;ALTID=1;LANGUAGE=en:Boss TITLE;ALTID=2;LANGUAGE=en:Chief vCard Evangelist ]]>