Position 106 is where the field starts which contains "VALD" or "WETH". When the value of the field changes, the total ptorcessing for the previous value is done, and the heading set-up for the new value is done. Spacial cases are firstl record, no totalling, and last record, no heading set-up.
Again, records do not have fields. Records contain data. The meaning of that data, depending on the file, can change from record to record or be the same from record to record, but the only thing which tells a program that is the program itself.
They "broke it at 106" because 1) that's where one the record, of this single-record-type file, the data which indicates publoisher, in the case of this program, the break field, is and 2) 106 is the position of the field on the record not the record on the file.
Can you tell us how you have been using the document? You have some conceptual problems we need to deal with, otherwise we explain, you say "yes, I know that" then proceeed to show that you don't.