diff --git a/INSTALL_testprogs b/INSTALL_testprogs
index 7d63812c1e61e448cc838ad36c63031225abf48f..eed314f13a5e3376d7d350e78236d9e432fd52db 100644
--- a/INSTALL_testprogs
+++ b/INSTALL_testprogs
@@ -4,3 +4,12 @@ These data are generated according to the description provided in the Offline do
 The check_commit_testprogs.sh script will run offline simulations in the directory given
 by the environment variable TESTPROGSDIR ($HOME/TESTPROGS will be used if the variable is not set).
 This directory must exist.
+
+The goal of the script is to compare outputs between two simulations (to check if bit-reproducibilty
+is achieved or not).
+A reference simulation must be performed and save. This reference simulation is run the same way as the
+test experiment but cannot be compared to something else:
+check_commit_testprogs.sh -c -r <reference_commit>
+
+If this reference simulation must become the 'absolute' reference (used when invoking the check_commit_testprogs.sh
+script with the 'REF' argument), the reference simulation directory (under $TESTPROGSDIR) must be renamed 'ref'.
diff --git a/check_commit_testprogs.sh b/check_commit_testprogs.sh
index 46cca3aad0433f4a456d8a9caec13804606352c8..16a70e2bd970041372894a1f224096969dedf245 100755
--- a/check_commit_testprogs.sh
+++ b/check_commit_testprogs.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
 
-set -x
+#set -x
 set -e
 
 #This script: