An occurrence of information being transmitted; e.g. an alert that was sent to a responsible provider, a public health agency was notified about a reportable condition. An occurrence of information being transmitted; e.g. an alert that was sent to a responsible provider, a public health agency was notified about a reportable condition. If the element is present, it must have either a @value, an @id, or extensions Identifiers associated with this Communication that are defined by business processes and/ or used to refer to it when a direct URL reference to the resource itself is not appropriate (e.g. in CDA documents, or in written / printed documentation). The type of message conveyed such as alert, notification, reminder, instruction, etc. The entity (e.g. person, organization, clinical information system, or device) which was the source of the communication. The entity (e.g. person, organization, clinical information system, or device) which was the target of the communication. If receipts need to be tracked by individual, a separate resource instance will need to be created for each recipient.  Multiple recipient communications are intended where either a receipt(s) is not tracked (e.g. a mass mail-out) or is captured in aggregate (all emails confirmed received by a particular time). Text, attachment(s), or resource(s) that was communicated to the recipient. A channel that was used for this communication (e.g. email, fax). The status of the transmission. The encounter within which the communication was sent. The time when this communication was sent. The time when this communication arrived at the destination. The reason or justification for the communication. The patient who was the focus of this communication. The communication request that was responsible for producing this communication. An occurrence of information being transmitted; e.g. an alert that was sent to a responsible provider, a public health agency was notified about a reportable condition. A communicated content (or for multi-part communications, one portion of the communication). The communication transmission is ongoing. The message transmission is complete, i.e., delivered to the recipient's destination. The communication transmission has been held by originating system/user request. The receiving system has declined to accept the message. There was a failure in transmitting the message out. The status of the communication. If the element is present, it must have either a @value, an @id, or extensions