Jim, 
They are additional OBX segments 
Here is an example. 
I am recieving the message
OBX|001|TX|RAD||||||||P|
OBX|002|TX|RAD||BIRTHDATE:  05/17/1932||||||P|
OBX|003|TX|RAD||||||||P|
OBX|004|TX|RAD||||||||P|
OBX|005|TX|RAD||ADDENDUM||||||P|
OBX|006|TX|RAD||Text Text Text||||||P|
OBX|007|TX|RAD||Text Text Text||||||P|
OBX|008|TX|RAD||Text Text Text||||||P|
OBX|009|TX|RAD||Text Text Text||||||P|
OBX|010|TX|RAD||Text Text Text||||||P|
OBX|011|TX|RAD||Text Text Text.||||||P|
OBX|012|TX|RAD||||||||P|
OBX|013|TX|RAD||||||||P|
OBX|014|TX|RAD||||||||P|
OBX|015|TX|RAD||                                   ______________________________||||||P|
OBX|016|TX|RAD||                                   BETH LINDSAY, M.D.||||||P|
OBX|017|TX|RAD||||||||P|
OBX|018|TX|RAD||Date:_________Time:____________||||||P|
OBX|019|TX|RAD||||||||P|
OBX|020|TX|RAD||||||||P|
OBX|021|TX|RAD||BL/MEDQ/7901571||||||P|
OBX|022|TX|RAD||DD:  09/23/2009 13:27:52||||||P|
OBX|023|TX|RAD||DT:  09/24/2009 02:26:02||||||P|
OBX|024|TX|RAD||JOB# 464357||||||P|
OBX|025|TX|RAD||||||||P|
OBX|026|TX|RAD||cc:   David Mack, M.D.||||||P|
OBX|027|TX|RAD||||||||P|
OBX|028|TX|RAD||Hope D. Hall-Wilson, M.D.||||||P|
OBX|029|TX|RAD||Fax: 492-3492||||||P|
OBX|030|TX|RAD||||||||P|
OBX|031|TX|RAD||Robert F. Noel Jr., M.D.||||||P|
OBX|032|TX|RAD||||||||P|
and they would like 
0(0).OBX(0)  :  >|001|TX|RAD||Maria Parham Medical Center||||||P<
0(0).OBX(1)  :  >|002|TX|RAD||ONCOLOGY ||||||P<
0(0).OBX(2)  :  >|003|TX|RAD||Patient’s Name||||||P<
0(0).OBX(3)  :  >|004|TX|RAD||1259371||||||P<
Placed on the top of the messages 
So right now I was trying to just place the text in 001-004 and push the rest of the message down – this would work great if every message was the same length.  but when i place them in 001 – 004 and move the rest of the lines down once i get down into the message it starts overwriting text in the message.