Index: trunk/ppMerge/src/ppMergeOptions.c
===================================================================
--- trunk/ppMerge/src/ppMergeOptions.c	(revision 16842)
+++ trunk/ppMerge/src/ppMergeOptions.c	(revision 16950)
@@ -23,4 +23,6 @@
     psFree(options->format);
     psFree(options->combine);
+    psFree(options->darkOrdinates);
+    psFree(options->darkNorm);
 }
 
@@ -68,4 +70,5 @@
     options->growPixels = 0;
     options->darkOrdinates = NULL;
+    options->darkNorm = NULL;
     return options;
 }
@@ -309,4 +312,9 @@
         }
         psFree(iter);
+
+        psString darkNorm = psMetadataLookupStr(NULL, recipe, "DARK.NORM"); // Normalisation concept
+        if (darkNorm && strcmp(darkNorm, "NONE") != 0) {
+            options->darkNorm = psStringCopy(darkNorm);
+        }
     }