3270 stream generated by Natural

I have some questions regarding the rules Natural generates 3270 stream from a map.

  1. Let’s say there is a sequence of fields like the following:
    0100 008T FELD001 (AD=OIL ) /.01U004 A004 .
    0101 013T FELD002 (AD=OIL ) /
    .01U004 A004 .
    0102 018T FELD003 (AD=OIL ) /.01U002 A002 .
    0103 021T FELD004 (AD=OIL ) /
    .01U002 A002 .
    In the 3270, there’s just one field which begins in column 8 and spans over all the 4 fields above. Is that some kind of compression? Can it be predicted when parsing the map?
  2. For the following sequence of fields:
    0200 060T FELD60 (AD=OIL ) /*.01U002 A012 .
    0201 /
    0202 001T ‘POLICY’
    the last 8 characters of the first row are combined with the first field of the next row to produce a 3270 field like this:

I’m building a 3270 parser for Natural, and understanding of these phenomena is very important.