Index: /trunk/ippTools/src/difftool.c
===================================================================
--- /trunk/ippTools/src/difftool.c	(revision 30069)
+++ /trunk/ippTools/src/difftool.c	(revision 30070)
@@ -1978,4 +1978,5 @@
     PXOPT_COPY_STR(config->args, stack2Where, "-skycell_id", "stackRun.skycell_id", "==");
     PXOPT_COPY_STR(config->args, stack1Where, "-input_label", "stackRun.label","==");
+    PXOPT_COPY_STR(config->args, stack1Where, "-input_data_group", "stackRun.data_group","==");
     PXOPT_COPY_STR(config->args, stack2Where, "-template_label", "stackRun.label","==");
     PXOPT_COPY_F32(config->args, stack1Where, "-good_frac", "stackSumSkyfile.good_frac", ">=");
Index: /trunk/ippTools/src/difftoolConfig.c
===================================================================
--- /trunk/ippTools/src/difftoolConfig.c	(revision 30069)
+++ /trunk/ippTools/src/difftoolConfig.c	(revision 30070)
@@ -336,4 +336,5 @@
     psMetadataAddStr(definestackstackArgs, PS_LIST_TAIL, "-input_label", 0, "search by stack label for input", NULL);
     psMetadataAddStr(definestackstackArgs, PS_LIST_TAIL, "-template_label", 0, "search by stack label for template", NULL);
+    psMetadataAddStr(definestackstackArgs, PS_LIST_TAIL, "-input_data_group", 0, "search by stack data_group for input", NULL);
     psMetadataAddF32(definestackstackArgs, PS_LIST_TAIL, "-good_frac", 0, "minimum good fraction of skycell", NAN);
     psMetadataAddStr(definestackstackArgs, PS_LIST_TAIL, "-set_workdir", 0, "define workdir (required)", NULL);