diff --git a/sohstationviewer/model/data_loader.py b/sohstationviewer/model/data_loader.py
index 5d813e82d9361c51b41840e9dd2ea00b01901838..c42470427a8f4d66894fd24035ee9ea6011af3fc 100644
--- a/sohstationviewer/model/data_loader.py
+++ b/sohstationviewer/model/data_loader.py
@@ -171,6 +171,8 @@ class DataLoader(QtCore.QObject):
         :param include_mp456: if mass position channels 4,5,6 are requested
         :param rt130_log_files: list of paths to RT130 log files selected by
             the user
+        :param include_masspos_in_soh_messages: whether to include
+            mass-position data in RT130 SOH messages
         """
         if self.running:
             # TODO: implement showing an error window
diff --git a/sohstationviewer/model/reftek_data/reftek.py b/sohstationviewer/model/reftek_data/reftek.py
index 39eff98f238e4b6ae98cfa4ae544fdb53b646485..eb20e061e88df3c5ed9971fe9e4c7a493202a8de 100755
--- a/sohstationviewer/model/reftek_data/reftek.py
+++ b/sohstationviewer/model/reftek_data/reftek.py
@@ -141,6 +141,8 @@ class RT130(GeneralData):
             soh_header = ''
             soh_footer = ''
             soh_messages = self.log_data[key]['SOH']
+            # We want to include a log file header only when there is not
+            # already one.
             possible_programs = ['logpeek', 'SOHStationViewer', 'rt2ms']
             message_has_header = any(soh_messages[0].startswith(program)
                                      for program