Index: trunk/Mars/ceres.cc
===================================================================
--- trunk/Mars/ceres.cc	(revision 19848)
+++ trunk/Mars/ceres.cc	(revision 19849)
@@ -65,4 +65,7 @@
     gLog << "   --ind=path                Input path of Corsika files if sequence used" << endl;
     gLog << "                              [def=standard path in datacenter]" << endl;
+    gLog << "   --check                   Can be used to check whether the input files are valid." << endl;
+    gLog << "                             0 is returned in case of success. Warnings can be" << endl;
+    gLog << "                             suppressed with -v1." << endl;
     gLog << "   --outf=filename           Output filename. Combines all input files into" << endl;
     gLog << "                              one output file. (Note that the output file will" << endl;