N command code
The N command code prevents you from replacing a segment on a path call. In conjunction with the D command code, it lets the application program to process multiple segments using one call. Alone, the D command code retrieves a path of segments in your I/O area. With the N command code, the D command code lets you distinguish which segments you want to replace.
For example, the following code only replaces the TREATMNT segment.
GHU PATIENT*D(PATNObbb=b06439)
ILLNESSb*D(ILLDATEb=19930301)
TREATMNT
REPL PATIENT*N(PATNObbb=b06439)
ILLNESSb*N(ILLDATEb=19930301)
TREATMNT
Restriction: If you use D and N command codes together, IMS™ retrieves the segment but does
not replace it.
The N command code applies only to REPL calls, and IMS ignores it if you include the code in any other call.