Example of Sub Header splitter

After a split, every message created may contain a sub-header with one or several of these data:

System/Sub-system (U)
Reference Number (R)
Note (N)
Text (T)

Example: file split 1

Header (H1)
Sub-Header (S1)
System/Sub-system (U)
Reference Number (R)
Note (N)
Text (T)
Trailer (Z1)

Example: file split 2

Header (H2)
Sub-Header (S1)
System/Sub-system (U)
Reference Number (R)
Note (N)
Text (T)
Trailer (Z2)