Index: trunk/ppSub/src/ppSubReadout.c
===================================================================
--- trunk/ppSub/src/ppSubReadout.c	(revision 14526)
+++ trunk/ppSub/src/ppSubReadout.c	(revision 14536)
@@ -44,4 +44,9 @@
     pmCell *outCell = pmFPAfileThisCell(config->files, view, "PPSUB.OUTPUT"); // Output cell
     pmReadout *outRO = pmReadoutAlloc(outCell); // Output readout
+    pmFPA *outFPA = outCell->parent->parent; // Output FPA
+    pmHDU *outHDU = outFPA->hdu; // Output HDU
+    if (!outHDU->header) {
+        outHDU->header = psMetadataAlloc();
+    }
 
     psImage *input = inRO->image;       // Input image
@@ -287,4 +292,7 @@
     }
 
+    // Add kernel descrption to header
+    psMetadataAddStr(outHDU->header, PS_LIST_TAIL, "PPSUB.KERNEL", 0,
+                     "Subtraction kernel", kernels->description);
     psFree(kernels);
 
@@ -341,6 +349,4 @@
     pmFPA *refFPA = refRO->parent->parent->parent; // Reference FPA
     pmHDU *refHDU = refFPA->hdu;        // Reference HDU
-    pmFPA *outFPA = outCell->parent->parent; // Output FPA
-    pmHDU *outHDU = outFPA->hdu; // Output HDU
     if (!outHDU || !refHDU) {
         psWarning("Unable to find HDU at FPA level to copy astrometry.");
@@ -350,7 +356,4 @@
             psFree(outRO);
             return false;
-        }
-        if (!outHDU->header) {
-            outHDU->header = psMetadataAlloc();
         }
         if (!pmAstromWriteWCS(outHDU->header, outFPA, outCell->parent, WCS_TOLERANCE)) {