Name Flags Card. Type Description & Constraints doco
. . Bundle N Resource Contains a collection of resources
+ Rule: total only when a search or history
+ Rule: entry.search only when a search
+ Rule: FullUrl must be unique in a bundle, or else entries with the same fullUrl must have different meta.versionId (except in history bundles)
+ Rule: A document must have an identifier with a system and a value
+ Rule: A document must have a date
+ Rule: A document must have a Composition as the first resource
+ Rule: A message must have a MessageHeader as the first resource
+ Rule: A subscription-notification must have a SubscriptionStatus as the first resource
+ Rule: entry.request.method PATCH not allowed for history
+ Rule: Bundle resources where type is not transaction, transaction-response, batch, or batch-response or when the request is a POST SHALL have Bundle.entry.fullUrl populated
+ Rule: Issue.severity for all issues within the OperationOutcome must be either 'information' or 'warning'.
+ Rule: Use and meaning of issues for documents has not been validated because the content will not be rendered in the document.
+ Rule: Self link is required for searchsets.
+ Rule: For collections of type document, message, searchset or collection, all entries must contain resources, and not have request or response elements
+ Rule: For collections of type history, all entries must contain request or response elements, and resources if the method is POST, PUT or PATCH
+ Rule: For collections of type transaction or batch, all entries must contain request elements, and resources if the method is POST, PUT or PATCH
+ Rule: For collections of type transaction-response or batch-response, all entries must contain response elements

Elements defined in Ancestors: id, meta, implicitRules, language
. . . identifier Σ C 0..1 Identifier Persistent identifier for the bundle
. . . type Σ C 1..1 code document | message | transaction | transaction-response | batch | batch-response | history | searchset | collection | subscription-notification
Binding: Bundle Type ( Required)
. . . timestamp Σ C 0..1 instant When the bundle was assembled
. . . total Σ C 0..1 unsignedInt If search, the total number of matches
. . . link Σ C 0..* BackboneElement Links related to this Bundle

. . . . relation Σ C 1..1 code See http://www.iana.org/assignments/link-relations/link-relations.xhtml#link-relations-1
Binding: Link Relation Types ( Required)
. . . . url Σ C 1..1 uri Reference details for the link
. . . entry Σ C 0..* BackboneElement Entry in the bundle - will have a resource or information
+ Rule: must be a resource unless there's a request or response
+ Rule: fullUrl cannot be a version specific reference
This repeating element order: For bundles of type 'document' and 'message', the first resource is special (must be Composition or MessageHeader respectively). For all bundles, the meaning of the order of entries depends on the bundle type
. . . . link Σ 0..* see link Links related to this entry

. . . . fullUrl Σ C 0..1 uri URI for resource (e.g. the absolute URL server address, URI for UUID/OID, etc.)
. . . . resource Σ C 0..1 Resource A resource in the bundle
. . . . search Σ C 0..1 BackboneElement Search related information
. . . . . mode Σ 0..1 code match | include - why this is in the result set
Binding: Search Entry Mode ( Required)
. . . . . score Σ 0..1 decimal Search ranking (between 0 and 1)
. . . . request Σ C 0..1 BackboneElement Additional execution information (transaction/batch/history)
. . . . . method Σ C 1..1 code GET | HEAD | POST | PUT | DELETE | PATCH
Binding: H T T P Verb ( Required)
. . . . . url Σ 1..1 uri URL for HTTP equivalent of this entry
. . . . . ifNoneMatch Σ 0..1 string For managing cache validation
. . . . . ifModifiedSince Σ 0..1 instant For managing cache currency
. . . . . ifMatch Σ 0..1 string For managing update contention
. . . . . ifNoneExist Σ 0..1 string For conditional creates
. . . . response Σ C 0..1 BackboneElement Results of execution (transaction/batch/history)
. . . . . status Σ 1..1 string Status response code (text optional)
. . . . . location Σ 0..1 uri The location (if the operation returns a location)
. . . . . etag Σ 0..1 string The Etag for the resource (if relevant)
. . . . . lastModified Σ 0..1 instant Server's date time modified
. . . . . outcome Σ 0..1 Resource OperationOutcome with hints and warnings (for batch/transaction)
. . . signature Σ TU 0..1 Signature Digital Signature
. . . issues Σ C TU 0..1 Resource Issues with the Bundle

doco Documentation for this format