Begin Named Group (BNG) structured field

When ACIF processes an AFP data stream print file that contains page groups, it checks for an FQN type X'01' triplet on each BNG structured field. If the FQN triplet exists, ACIF uses the value when it creates an FQN type X'0D' triplet on the corresponding Index Element (IEL) structured field in the index object file. ACIF appends an 8-byte rolling sequence number to ensure uniqueness in the name. If no FQN triplet exists, ACIF creates one and, unless UNIQUEBNGS=NO is specified, appends a rolling, 8-byte EBCDIC sequence number to ensure uniquely named groups, up to a maximum of 99999999 groups within a print file.

When ACIF indexes a print file, it creates the BNG structured fields. It assigns a rolling 8-byte EBCDIC sequence number to the token name (for example, 00000001 where 1=X'F1'). The sequence number begins with 00000001 and is incremented by 1 each time a group is created. Unless UNIQUEBNGS=NO is specified, ACIF also creates an FQN type X'01' triplet by concatenating the specified index value (GROUPNAME) with the same sequence number used in the token name. If the value of the index that is specified in GROUPNAME is too long, the trailing bytes are replaced by the sequence number. This situation occurs only if the specified index value exceeds 242 bytes in length. A maximum of 99999999 groups can be supported before the counter wraps, which means that ACIF ensures a maximum of 99999999 unique group names.