A reference for additional message identification, assigned by the requesting host system. When a request message includes an echo token the corresponding response message MUST include an echo token with an identical value.

Used to identify the sequence number of the transaction as assigned by the sending system; allows for an application to process messages in a certain order or to request a resynchronization of messages in the event that a system has been off-line and needs to retrieve messages that were missed.

This is used to respond to a CapabilitiesRQ, where the target system responds describing its available level of functionality.

Used to indicate whether the request is for the Test or Production system.

A unique identifier to relate all messages within a transaction (e.g. this would be sent in all request and response messages that are part of an on-going transaction).

When true, indicates the message is being re-sent after a failure. It is recommended that this attribute is used (i.e., set to TRUE) only when a message is retransmitted.

For all OTA versioned messages, the version of the message is indicated by a decimal value.

This indicates where this message falls within a sequence of messages.

Identifies the alternate language for a customer or message. The human language is identified by ISO 639 codes.

Indicates the creation date and time of the message in UTC using the following format specified by ISO 8601; YYYY-MM-DDThh:mm:ssZ with time values using the 24 hour clock (e.g. 20 November 2003, 1:59:38 pm UTC becomes 2003-11-20T13:59:38Z).

When true, indicates that names (and all other details) are required for *all* customers.

Identifes the primary language preference for the message. The human language is identified by ISO 639 codes.

When 'true, indicates that this system can accept multiple items in a request.

When true, indicates that this system can support customer suballocation (not all customers on all items).