Data Type Formal Definitions

This page is part of the FHIR Specification (v0.0.82: DSTU 1). The current version which supercedes this version is 5.0.0. For a full list of available versions, see the Directory of published versions . Page versions: R5 R4B R4 R3 R2

1.13.2 Data Type Formal Definitions

This page provides the formal definitions for the data types

1.13.2.1 Attachment

See also Base Definition, Examples and Mappings.

Attachment
Definition	For referring to data content defined in other formats.
Control	1..1
Requirements	Many models need to include data defined in other specifications that is complex and opaque to the healthcare model. This includes documents, media recordings, structured data, etc.
Attachment.contentType
Definition	Identifies the type of the data in the attachment and allows a method to be chosen to interpret or render the data. Includes mime type parameters such as charset where appropriate.
Control	1..1
Binding	MimeType: see BCP 13 (RFCs 2045, 2046, 2047, 4288, 4289 and 2049)
Type	code
Requirements	Processors of the data need to be able to know how to interpret the data.
Attachment.language
Definition	The human language of the content. The value can be any valid value according to BCP 47.
Control	0..1
Binding	Language: see IETF language tag
Type	code
Requirements	Users need to be able to choose between the languages in a set of attachments.
Attachment.data
Definition	The actual data of the attachment - a sequence of bytes. In XML, represented using base64.
Control	0..1
Type	base64Binary
Requirements	The data needs to able to be transmitted inline.
Comments	The base64-encoded data SHALL be expressed in the same character set as the base resource XML or JSON.
Attachment.url
Definition	An alternative location where the data can be accessed.
Control	0..1
Type	uri
Requirements	The data needs to be transmitted by reference.
Comments	If both data and url are provided, the url SHALL point to the same content as the data contains. Urls may be relative references or may reference transient locations such as a wrapping envelope using cid: though this has ramifications for using signatures. Relative URLs are interpreted relative to the service url, like a resource reference, rather than relative to the resource itself. If a URL is provided, it SHALL resolve to actual data.
Attachment.size
Definition	The number of bytes of data that make up this attachment.
Control	0..1
Type	integer
Requirements	Representing the size allows applications to determine whether they should fetch the content automatically in advance, or refuse to fetch it at all.
Comments	The number of bytes is redundant if the data is provided as a base64binary, but is useful if the data is provided as a url reference.
Attachment.hash
Definition	The calculated hash of the data using SHA-1. Represented using base64.
Control	0..1
Type	base64Binary
Requirements	Included so that applications can verify that the contents of a location have not changed and so that a signature of the content can implicitly sign the content of an image without having to include the data in the instance or reference the url in the signature.
Attachment.title
Definition	A label or set of text to display in place of the data.
Control	0..1
Type	string
Requirements	Applications need a label to display to a human user in place of the actual data if the data cannot be rendered or perceived by the viewer.

1.13.2.2 Identifier

See also Base Definition, Examples and Mappings.

Identifier
Definition	A technical identifier - identifies some entity uniquely and unambiguously.
Control	1..1
Requirements	Need to be able to identify things with confidence and be sure that the identification is not subject to misinterpretation.
Identifier.use
Definition	The purpose of this identifier.
Control	0..1
Binding	IdentifierUse: Identifies the purpose for this identifier, if known (see http://hl7.org/fhir/identifier-use for values)
Type	code
Is Modifier	true
Requirements	Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers.
Comments	This is labeled as "Is Modifier" because applications should not mistake a temporary id for a permanent one. Applications can assume that an identifier is permanent unless it explicitly says that it is temporary.
Identifier.label
Definition	A text string for the identifier that can be displayed to a human so they can recognize the identifier.
Control	0..1
Type	string
Requirements	Allows humans to make use of identifiers when the identifier system is not known.
Identifier.system
Definition	Establishes the namespace in which set of possible id values is unique.
Control	0..1
Type	uri
Requirements	There are many sequences of identifiers. To perform matching, we need to know what sequence we're dealing with. The system identifies a particular sequence or set of unique identifiers.
Identifier.value
Definition	The portion of the identifier typically displayed to the user and which is unique within the context of the system.
Control	0..1
Type	string
Comments	If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986.
Identifier.period
Definition	Time period during which identifier is/was valid for use.
Control	0..1
Type	Period
Identifier.assigner
Definition	Organization that issued/manages the identifier.
Control	0..1
Type	Resource(Organization)
Comments	The reference may be just a text description of the assigner.

1.13.2.3 Coding

See also Base Definition, Examples and Mappings.

Coding
Definition	A reference to a code defined by a terminology system.
Control	1..1
Requirements	References to codes are very common in healthcare models.
Comments	Codes may be defined very casually in enumerations or code lists, up to very formal definitions such as SNOMED CT - see the V3 Core Principles for more information.
Invariants	Defined on this element Inv-1: If a valueSet is provided, a system URI Is required (xpath: not (exists(f:valueSet) and exists(f:code)) or exists(f:system))
Coding.system
Definition	The identification of the code system that defines the meaning of the symbol in the code.
Control	0..1
Type	uri
Requirements	Need to be unambiguous about the source of the definition of the symbol.
Comments	The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should de-reference to some definition that establish the system clearly and unambiguously.
Coding.version
Definition	The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured. and When the meaning is not guaranteed to be consistent, the version SHOULD be exchanged.
Control	0..1
Type	string
Coding.code
Definition	A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).
Control	0..1
Type	code
Requirements	Need to refer to a particular code in the system.
Coding.display
Definition	A representation of the meaning of the code in the system, following the rules of the system.
Control	0..1
Type	string
Requirements	Need to be able to carry a human-readable meaning of the code for readers that do not know the system.
Coding.primary
Definition	Indicates that this code was chosen by a user directly - i.e. off a pick list of available items (codes or displays).
Control	0..1
Type	boolean
Requirements	This has been identified as a clinical safety criterium - that this exact code was chosen explicitly, rather than inferred by the system based on some rules or language processing.
Comments	Amongst a set of alternatives, a directly chosen code is the most appropriate starting point for new translations.
Coding.valueSet
Definition	The set of possible coded values this coding was chosen from or constrained by.
Control	0..1
Type	Resource(ValueSet)
Requirements	The value set may influence the codes that the user can select. Also, referencing the value set directly makes it easier to share ad-hoc code systems used across healthcare.

1.13.2.4 CodeableConcept

See also Base Definition, Examples and Mappings.

CodeableConcept
Definition	A concept that may be defined by a formal reference to a terminology or ontology or may be provided by text.
Control	1..1
Requirements	This is a common pattern in healthcare - a concept that may be defined by one or more codes from formal definitions including LOINC and SNOMED CT, and/or defined by the provision of text that captures a human sense of the concept.
Comments	Not all terminology uses fit this general pattern. In some cases, models should not use CodeableConcept and use Coding directly and provide their own structure for managing text, codings, translations and the relationship between elements and pre- and post-coordination.
Invariants	Defined on this element Inv-2: Only one coding in a set can be chosen directly by the user (xpath: count(f:coding[f:primary/@value='true'])<1)
CodeableConcept.coding
Definition	A reference to a code defined by a terminology system.
Control	0..*
Type	Coding
Requirements	Allows for translations and alternate encodings within a code system. Also supports communication of the same instance to systems requiring different encodings.
Comments	Codes may be defined very casually in enumerations, or code lists, up to very formal definitions such as SNOMED CT - see the V3 Core Principles for more information. Ordering of codings is undefined and SHALL not be used to infer meaning.
CodeableConcept.text
Definition	A human language representation of the concept as seen/selected/uttered by the user who entered the data and/or which represents the intended meaning of the user.
Control	0..1
Type	string
Requirements	The codes from the terminologies do not always capture the correct meaning with all the nuances of the human using them, or sometimes there is no appropriate code at all. In these cases, the text is used to capture the full meaning of the source.
Comments	Very often the text is the same as a displayName of one of the codings.

1.13.2.5 Quantity

See also Base Definition, Examples and Mappings.

Quantity
Definition	A measured amount (or an amount that can potentially be measured). Note that measured amounts include amounts that are not precisely quantified, including amounts involving arbitrary units and floating currencies.
Control	1..1
Requirements	Need to able to capture all sorts of measured values, even if the measured value are not precisely quantified. Values include exact measures such as 3.51g, customary units such as 3 tablets, and currencies such as $100.32USD.
Comments	The context of use may frequently define what kind of quantity this is and therefore what kind of units can be used. The context of use may also restrict the values for the comparator.
Invariants	Defined on this element Inv-3: If a code for the units is present, the system SHALL also be present (xpath: not(exists(f:code)) or exists(f:system))
Quantity.value
Definition	The value of the measured amount. The value includes an implicit precision in the presentation of the value.
Control	0..1
Type	decimal
Requirements	Precision is handled implicitly in almost all cases of measurement.
Comments	The implicit precision in the value should always be honored. Monetary values have their own rules for handling precision (refer to standard accounting text books).
Quantity.comparator
Definition	How the value should be understood and represented - whether the actual value is greater or less than the stated value due to measurement issues. E.g. if the comparator is "<" , then the real value is < stated value.
Control	0..1
Binding	QuantityCompararator: How the Quantity should be understood and represented (see http://hl7.org/fhir/quantity-comparator for values)
Type	code
Is Modifier	true
Requirements	Need a framework for handling measures where the value is <5ug/L or >400mg/L due to the limitations of measuring methodology.
Comments	This is labeled as "Is Modifier" because the comparator modifies the interpretation of the value significantly. If there is no comparator, then there is no modification of the value.
Quantity.units
Definition	A human-readable form of the units.
Control	0..1
Type	string
Requirements	There are many representations for units and in many contexts, particular representations are fixed and required. I.e. mcg for micrograms.
Quantity.system
Definition	The identification of the system that provides the coded form of the unit.
Control	0..1
Type	uri
Requirements	Need to know the system that defines the coded form of the unit.
Invariants	Affect this element Inv-3: If a code for the units is present, the system SHALL also be present (xpath: not(exists(f:code)) or exists(f:system))
Quantity.code
Definition	A computer processable form of the units in some unit representation system.
Control	0..1
Type	code
Requirements	Need a computable form of the units that is fixed across all forms. UCUM provides this for quantities, but SNOMED CT provides many units of interest.
Comments	The preferred system is UCUM, but SNOMED CT can also be used (for customary units) or ISO 4217 for currency. The context of use may additionally require a code from a particular system (Unless the Quantity element has a dataAbsentReason flag).

1.13.2.6 Range

See also Base Definition, Examples and Mappings.

Range
Definition	A set of ordered Quantities defined by a low and high limit.
Control	1..1
Requirements	Need to be able to specify ranges of values.
Comments	The stated low and high value are assumed to have arbitrarily high precision when it comes to determining which values are in the range. I.e. 1.99 is not in the range 2 -> 3.
Invariants	Defined on this element Inv-2: If present, low SHALL have a lower value than high (xpath: not(exists(f:low/f:value/@value)) or not(exists(f:high/f:value/@value)) or (number(f:low/f:value/@value) <= number(f:high/f:value/@value))) Inv-3: Quantity values cannot have a comparator when used in a Range (xpath: not(exists(f:low/f:comparator) or exists(f:high/f:comparator)))
Range.low
Definition	The low limit. The boundary is inclusive.
Control	0..1
Type	Quantity
Comments	If the low element is missing, the low boundary is not known.
Invariants	Affect this element Inv-2: If present, low SHALL have a lower value than high (xpath: not(exists(f:low/f:value/@value)) or not(exists(f:high/f:value/@value)) or (number(f:low/f:value/@value) <= number(f:high/f:value/@value))) Inv-3: Quantity values cannot have a comparator when used in a Range (xpath: not(exists(f:low/f:comparator) or exists(f:high/f:comparator)))
Range.high
Definition	The high limit. The boundary is inclusive.
Control	0..1
Type	Quantity
Comments	If the high element is missing, the high boundary is not known.
Invariants	Affect this element Inv-2: If present, low SHALL have a lower value than high (xpath: not(exists(f:low/f:value/@value)) or not(exists(f:high/f:value/@value)) or (number(f:low/f:value/@value) <= number(f:high/f:value/@value))) Inv-3: Quantity values cannot have a comparator when used in a Range (xpath: not(exists(f:low/f:comparator) or exists(f:high/f:comparator)))

1.13.2.7 Ratio

See also Base Definition, Examples and Mappings.

Ratio
Definition	A relationship of two Quantity values - expressed as a numerator and a denominator.
Control	1..1
Requirements	Need to able to capture ratios for some measurements (titers) and some rates (costs).
Invariants	Defined on this element Inv-1: numerator and denominator SHALL both be present, or both be absent (xpath: count(f:numerator) = count(f:denominator))
Ratio.numerator
Definition	The value of the numerator.
Control	0..1
Type	Quantity
Ratio.denominator
Definition	The value of the denominator.
Control	0..1
Type	Quantity

1.13.2.8 Period

See also Base Definition, Examples and Mappings.

Period
Definition	A time period defined by a start and end date and optionally time.
Control	1..1
Comments	This is not a duration - that's a measure of time (a separate type), but a duration that occurs at a fixed value of time. A Period specifies a range of time; the context of use will specify whether the entire range applies (e.g. "the patient was an inpatient of the hospital for this time range") or one value from the range applies (e.g. "give to the patient between these two times"). If a duration might be required, specify the type as Interval\|Duration.
Invariants	Defined on this element Inv-1: If present, start SHALL have a lower value than end (xpath: not(exists(f:start)) or not(exists(f:end)) or (f:start/@value <= f:end/@value))
Period.start
Definition	The start of the period. The boundary is inclusive.
Control	0..1
Type	dateTime
Comments	If the low element is missing, the meaning is that the low boundary is not known.
Invariants	Affect this element Inv-1: If present, start SHALL have a lower value than end (xpath: not(exists(f:start)) or not(exists(f:end)) or (f:start/@value <= f:end/@value))
Period.end
Definition	The end of the period. If the end of the period is missing, it means that the period is ongoing.
Control	0..1
Type	dateTime
Comments	The high value includes any matching date/time. i.e. 2012-02-03T10:00:00 is in a period that has a end value of 2012-02-03.
Invariants	Affect this element Inv-1: If present, start SHALL have a lower value than end (xpath: not(exists(f:start)) or not(exists(f:end)) or (f:start/@value <= f:end/@value))

1.13.2.9 SampledData

See also Base Definition, Examples and Mappings.

SampledData
Definition	A series of measurements taken by a device, with upper and lower limits. There may be more than one dimension in the data.
Control	1..1
Requirements	There is a need for a concise way to handle the data produced by devices that sample a physical state at a high frequency.
Comments	The data is not interpretable without at least origin, period, and dimensions, but these are optional to allow a separation between the template of measurement and the actual measurement, such as between DeviceCapabilities and DeviceLog.
SampledData.origin
Definition	The base quantity that a measured value of zero represents. In addition, this provides the units of the entire measurement series.
Control	1..1
Type	Quantity
SampledData.period
Definition	The length of time between sampling times, measured in milliseconds.
Control	1..1
Type	decimal
Comments	This is usually a whole number.
SampledData.factor
Definition	A correction factor that is applied to the sampled data points before they are added to the origin.
Control	0..1
Type	decimal
SampledData.lowerLimit
Definition	The lower limit of detection of the measured points. This is needed if any of the data points have the value "L" (lower than detection limit).
Control	0..1
Type	decimal
SampledData.upperLimit
Definition	The upper limit of detection of the measured points. This is needed if any of the data points have the value "U" (higher than detection limit).
Control	0..1
Type	decimal
SampledData.dimensions
Definition	The number of sample points at each time point. If this value is greater than one, then the dimensions will be interlaced - all the sample points for a point in time will be recorded at once.
Control	1..1
Type	integer
Comments	If there is more than one dimension, the code for the type of data will define the meaning of the dimensions (typically ECG data).
SampledData.data
Definition	A series of data points which are decimal values separated by a single space (character u20). The special values "E" (error), "L" (below detection limit) and "U" (above detection limit) can also be used in place of a decimal value.
Control	1..1
Type	string

1.13.2.10 HumanName

See also Base Definition, Examples and Mappings.

HumanName
Definition	A human's name with the ability to identify parts and usage.
Control	1..1
Requirements	Need to be able to record names, along with notes about their use.
Comments	Names may be changed, or repudiated, or people may have different names in different contexts. Names may be divided into parts of different type that have variable significance depending on context, though the division into parts does not always matter. With personal names, the different parts may or may not be imbued with some implicit meaning; various cultures associate different importance with the name parts and the degree to which systems must care about name parts around the world varies widely.
HumanName.use
Definition	Identifies the purpose for this name.
Control	0..1
Binding	NameUse: The use of a human name (see http://hl7.org/fhir/name-use for values)
Type	code
Is Modifier	true
Requirements	Allows the appropriate name for a particular context of use to be selected from among a set of names.
Comments	This is labeled as "Is Modifier" because applications should not mistake a temporary or old name etc for a current/permanent one. Applications can assume that a name is current unless it explicitly says that it is temporary or old.
HumanName.text
Definition	A full text representation of the name.
Control	0..1
Type	string
Requirements	A renderable, unencoded form.
Comments	Can provide both a text representation and structured parts.
HumanName.family
Definition	The part of a name that links to the genealogy. In some cultures (e.g. Eritrea) the family name of a son is the first name of his father.
Control	0..*
Type	string
Aliases	surname
Comments	For family name, hyphenated names such as "Smith-Jones" are a single name, but names with spaces such as "Smith Jones" are broken into multiple parts.
HumanName.given
Definition	Given name.
Control	0..*
Type	string
Aliases	first name; middle name
Comments	If only initials are recorded, they may be used in place of the full name. Not called "first name" since given names do not always come first.
HumanName.prefix
Definition	Part of the name that is acquired as a title due to academic, legal, employment or nobility status, etc. and that appears at the start of the name.
Control	0..*
Type	string
HumanName.suffix
Definition	Part of the name that is acquired as a title due to academic, legal, employment or nobility status, etc. and that appears at the end of the name.
Control	0..*
Type	string
HumanName.period
Definition	Indicates the period of time when this name was valid for the named person.
Control	0..1
Type	Period
Requirements	Allows names to be placed in historical context.

1.13.2.11 Address

See also Base Definition, Examples and Mappings.

Address
Definition	There is a variety of postal address formats defined around the world. This format defines a superset that is the basis for all addresses around the world.
Control	1..1
Requirements	Need to be able to record postal addresses, along with notes about their use.
Comments	Note: address is for postal addresses, not physical locations.
Address.use
Definition	The purpose of this address.
Control	0..1
Binding	AddressUse: The use of an address (see http://hl7.org/fhir/address-use for values)
Type	code
Is Modifier	true
Requirements	Allows an appropriate address to be chosen from a list of many.
Comments	This is labeled as "Is Modifier" because applications should not mistake a temporary or old address etc for a current/permanent one. Applications can assume that an address is current unless it explicitly says that it is temporary or old.
Address.text
Definition	A full text representation of the address.
Control	0..1
Type	string
Requirements	A renderable, unencoded form.
Comments	Can provide both a text representation and parts.
Address.line
Definition	This component contains the house number, apartment number, street name, street direction, P.O. Box number, delivery hints, and similar address information.
Control	0..*
Type	string
Requirements	home \| work \| temp \| old - purpose of this address.
Address.city
Definition	The name of the city, town, village or other community or delivery center.
Control	0..1
Type	string
Aliases	Muncipality
Address.state
Definition	Sub-unit of a country with limited sovereignty in a federally organized country. A code may be used if codes are in common use (i.e. US 2 letter state codes).
Control	0..1
Type	string
Aliases	Province; Territory
Address.zip
Definition	A postal code designating a region defined by the postal service.
Control	0..1
Type	string
Aliases	PostCode
Address.country
Definition	Country - a nation as commonly understood or generally accepted.
Control	0..1
Type	string
Comments	ISO 3166 3 letter codes can be used in place of a full country name.
Address.period
Definition	Time period when address was/is in use.
Control	0..1
Type	Period
Requirements	Allows addresses to be placed in historical context.

1.13.2.12 Contact

See also Base Definition, Examples and Mappings.

Contact
Definition	All kinds of technology mediated contact details for a person or organization, including telephone, email, etc.
Control	1..1
Requirements	Need to track phone, fax, mobile, sms numbers, email addresses, twitter tags, etc.
Invariants	Defined on this element Inv-2: A system is required if a value is provided. (xpath: not(exists(f:value)) or exists(f:system))
Contact.system
Definition	Telecommunications form for contact - what communications system is required to make use of the contact.
Control	0..1
Binding	ContactSystem: Telecommunications form for contact (see http://hl7.org/fhir/contact-system for values)
Type	code
Invariants	Affect this element Inv-2: A system is required if a value is provided. (xpath: not(exists(f:value)) or exists(f:system))
Contact.value
Definition	The actual contact details, in a form that is meaningful to the designated communication system (i.e. phone number or email address).
Control	0..1
Type	string
Requirements	Need to support legacy numbers that are not in a tightly controlled format.
Comments	Additional out of band data such as extensions, or notes about use of the contact are sometimes included in the value.
Contact.use
Definition	Identifies the purpose for the address.
Control	0..1
Binding	ContactUse: Location, type or status of telecommunications address indicating use (see http://hl7.org/fhir/contact-use for values)
Type	code
Is Modifier	true
Requirements	Need to track the way a person uses this contact, so a user can choose which is appropriate for their purpose.
Comments	This is labeled as "Is Modifier" because applications should not mistake a temporary or old contact etc for a current/permanent one. Applications can assume that a contact is current unless it explicitly says that it is temporary or old.
Contact.period
Definition	Time period when the contact was/is in use.
Control	0..1
Type	Period

1.13.2.13 Schedule

See also Base Definition, Examples and Mappings.

Schedule
Definition	Specifies an event that may occur multiple times. Schedules are used for to reord when things are expected or requested to occur.
Control	1..1
Requirements	Need to able to track schedules. There are several different ways to do scheduling: one or more specified times, a simple rules like three times a day, or before/after meals.
Comments	A schedule can be either a list of events - intervals on which the event occurs, or a single event with repeating criteria or just repeating criteria with no actual event.
Invariants	Defined on this element Inv-1: There can only be a repeat element if there is none or one event (xpath: not(exists(f:repeat)) or count(f:event) < 2)
Schedule.event
Definition	Identifies specific time periods when the event should occur.
Control	0..*
Type	Period
Requirements	Some schedules are just explicit lists of times.
Schedule.repeat
Definition	Identifies a repeating pattern to the intended time periods.
Control	0..1
Requirements	Many schedules are determined by regular repetitions.
Comments	If present, the Schedule.event indicates the time of the first occurrence.
Invariants	Defined on this element Inv-2: Either frequency or when SHALL be present, but not both (xpath: exists(f:frequency) != exists(f:when)) Inv-3: At most, only one of count or end can be present (xpath: not(exists(f:count) and exists(f:end))) Affect this element Inv-1: There can only be a repeat element if there is none or one event (xpath: not(exists(f:repeat)) or count(f:event) < 2)
Schedule.repeat.frequency
Definition	Indicates how often the event should occur.
Control	0..1
Type	integer
Invariants	Affect this element Inv-2: Either frequency or when SHALL be present, but not both (xpath: exists(f:frequency) != exists(f:when))
Schedule.repeat.when
Definition	Identifies the occurrence of daily life that determines timing.
Control	0..1
Binding	EventTiming: Real world event that the schedule relates to (see http://hl7.org/fhir/event-timing for values)
Type	code
Requirements	Timings are frequently determined by occurrences such as waking, eating and sleep.
Invariants	Affect this element Inv-2: Either frequency or when SHALL be present, but not both (xpath: exists(f:frequency) != exists(f:when))
Schedule.repeat.duration
Definition	How long each repetition should last.
Control	1..1
Type	decimal
Requirements	Some activities are not instantaneous and need to be maintained for a period of time.
Invariants	Defined on this element Inv-4: duration SHALL be a positive value (xpath: @value > 0 or not(@value)) Affect this element Inv-4: duration SHALL be a positive value (xpath: @value > 0 or not(@value))
Schedule.repeat.units
Definition	The units of time for the duration.
Control	1..1
Binding	UnitsOfTime: A unit of time (units from UCUM) (see http://hl7.org/fhir/units-of-time for values)
Type	code
Schedule.repeat.count
Definition	A total count of the desired number of repetitions.
Control	0..1
Type	integer
Requirements	Repetitions may be limited by end time or total occurrences.
Comments	An end need not be specified.
Invariants	Affect this element Inv-3: At most, only one of count or end can be present (xpath: not(exists(f:count) and exists(f:end)))
Schedule.repeat.end
Definition	When to stop repeating the schedule.
Control	0..1
Type	dateTime
Requirements	Repetitions may be limited by end time or total occurrences.
Comments	An end need not be specified.
Invariants	Affect this element Inv-3: At most, only one of count or end can be present (xpath: not(exists(f:count) and exists(f:end)))