How to specify variable-length segments
It is the data portion of a variable-length segment whose length varies. The data portion varies between a minimum and a maximum number of bytes.
As shown in the following figure, you specify minimum and maximum size in the BYTES= keyword in the SEGM statement in the DBD. Because IMS needs to know the length of the data portion of a variable-length segment, you include a 2-byte size field in each segment when loading it. The size field is in the data portion of the segment. The length of the data portion you specify must include the two bytes used for the size field. If the segment type has a sequence field, the minimum length specified in the size field must equal at least the size field and all data to the end of the sequence field.
