diff --git a/releng/README.core b/releng/README.core
index c6272a58..5260a9c8 100644
--- a/releng/README.core
+++ b/releng/README.core
@@ -21,7 +21,7 @@ Release Engineering
  + Well documented configuration file SCRIPT.conf.template
  + Throw FAIL string to stdout if any failure is detected
  + Return exit code 0 on success, non-zero on failure
- + Use different exit codes for any failure (range 1-31)
+ + Use different exit codes for any failure (range 0-31)
 
 * RUNNING TESTS
  + All tests have to be run from the releng/ directory, within
diff --git a/releng/releng_check_isocontent b/releng/releng_check_isocontent
index f96f3fb7..68a4265a 100755
--- a/releng/releng_check_isocontent
+++ b/releng/releng_check_isocontent
@@ -3,14 +3,34 @@
 set -e
 
 START_DIR_DONT_CHANGE=`pwd`
-
+SELF=$(basename "$0")
 # required config items
-XOR=""
-DIR=""
-IMG=""
+RELENG_XORRISO=""
+RELENG_DIR=""
+RELENG_IMG=""
 
-printf "\n$0: SCRIPT NOT COMPLETED YET\n"
-exit 100
+CONFFILE=$HOME/.libburnia-releng/${SELF}.conf
+KEEP=0
+GEN_DATA_DIR=releng_generated_data/${SELF}
+
+printf "\n$0: FAIL: SCRIPT NOT COMPLETED YET\n"
+exit 31
+
+print_help() {
+ cat << HLP
+Usage:
+ ${SELF} -help
+
+# using a config file ${CONFFILE}
+ ${SELF} -rc [-keep]
+
+# without using a config file
+ ${SELF} xorriso_cmd IN_dir OUT_image [-keep]
+
+# cleanup test generated data directory and exit
+ ${SELF} -cleanup
+HLP
+}
 
 
 # Thomas:
@@ -76,7 +96,7 @@ Sketched by Thomas:
   diff -r "$on_disk" "$copy_on_disk"
   if test "$?" -ne 0
   then
-    echo 'FAILURE !!!'
+    echo 'FAIL: Original disk tree and temporary tree differ'
   else
     echo "Success."
   fi