Segment: BAK Beginning Segment for Purchase Order Acknowledgment Position: 020 Loop: Level: Heading Usage: Mandatory Max Use: 1 Purpose: To indicate the beginning of the Purchase Order Acknowledgment Transaction Set and transmit identifying numbers and dates Syntax Notes: Semantic Notes: Comments: Notes:   Example:  BAK*00*AC*S911893215*19990428***AN3920943**19990428|  BAK*00*AD*S1704775*19990619***CT934982903**19990619!  BAK*00*AE*S915406071*19990603***9392039**19990603!     Data Element Summary                                                          Ref. Data   Des. Element Name Attributes M BAK01 353 Transaction Set Purpose Code M ID 2/2   Code identifying purpose of transaction set       00    Original   M BAK02 587 Acknowledgment Type M ID 2/2   Code specifying the type of acknowledgment       AC    Acknowledge - With Detail and Change   AD    Acknowledge - With Detail, No Change   AE    Acknowledge - With Exception Detail Only   M BAK03 324 Purchase Order Number M AN 1/22   Identifying number for Purchase Order assigned by the orderer/purchaser M BAK04 373 Purchase Order Date M DT 8/8   Date expressed as CCYYMMDD     The date assigned by the purchaser to the purchase order.     BAK07 367 Contract Number O AN 1/30   Contract number     Vendor's Reference Number   Must Use BAK09 373 Acknowledgment Date O DT 8/8   Date expressed as CCYYMMDD     The date assigned by the sender to the acknowledgment.   Previous Up Next                   855I4010 (004010) November 3, 1999