diff --git a/gramps/gen/lib/date.py b/gramps/gen/lib/date.py
index 947a0fb99..3b6c81cbc 100644
--- a/gramps/gen/lib/date.py
+++ b/gramps/gen/lib/date.py
@@ -296,6 +296,7 @@ class Span(object):
         @type dlocale: a GrampsLocale instance
         """
         trans_text = dlocale.translation.sgettext
+        # trans_text is a defined keyword (see po/update_po.py, po/genpot.sh)
         _repr = trans_text("unknown")
         # FIXME all this concatenation will fail for RTL languages
         if self.valid:
diff --git a/gramps/gen/lib/eventtype.py b/gramps/gen/lib/eventtype.py
index 0865d3158..34c9166b4 100644
--- a/gramps/gen/lib/eventtype.py
+++ b/gramps/gen/lib/eventtype.py
@@ -193,6 +193,7 @@ class EventType(GrampsType):
 
     def _T_(value): # enable deferred translations (see Python docs 22.1.3.4)
         return value
+    # _T_ is a gramps-defined keyword -- see po/update_po.py and po/genpot.sh
 
     _ABBREVIATIONS = {
         BIRTH: _T_("birth abbreviation|b."),
diff --git a/gramps/gen/plug/report/endnotes.py b/gramps/gen/plug/report/endnotes.py
index 2d6742dda..0f406f8c3 100644
--- a/gramps/gen/plug/report/endnotes.py
+++ b/gramps/gen/plug/report/endnotes.py
@@ -128,6 +128,7 @@ def write_endnotes(bibliography, database, doc, printnotes=False, links=False,
         return
 
     trans_text = elocale.translation.gettext
+    # trans_text is a defined keyword (see po/update_po.py, po/genpot.sh)
 
     doc.start_paragraph('Endnotes-Header')
     doc.write_text(trans_text('Endnotes'))
diff --git a/gramps/gen/relationship.py b/gramps/gen/relationship.py
index 5894a0055..f24477e64 100644
--- a/gramps/gen/relationship.py
+++ b/gramps/gen/relationship.py
@@ -1680,6 +1680,7 @@ class RelationshipCalculator(object):
             return ''
 
         trans_text = _
+        # trans_text is a defined keyword (see po/update_po.py, po/genpot.sh)
         if hasattr(self, '_locale') and self._locale != glocale:
             trans_text = self._locale.translation.sgettext
 
diff --git a/gramps/plugins/drawreport/statisticschart.py b/gramps/plugins/drawreport/statisticschart.py
index 2a01f5433..1625a50e5 100644
--- a/gramps/plugins/drawreport/statisticschart.py
+++ b/gramps/plugins/drawreport/statisticschart.py
@@ -310,6 +310,7 @@ class _options:
 
 def _T_(value): # enable deferred translations (see Python docs 22.1.3.4)
     return value
+# _T_ is a gramps-defined keyword -- see po/update_po.py and po/genpot.sh
 
 #------------------------------------------------------------------------
 #
diff --git a/gramps/plugins/lib/librecords.py b/gramps/plugins/lib/librecords.py
index a025b7e75..7a8613862 100644
--- a/gramps/plugins/lib/librecords.py
+++ b/gramps/plugins/lib/librecords.py
@@ -50,6 +50,7 @@ from gramps.gen.utils.alive import probably_alive
 
 def _T_(value): # enable deferred translations (see Python docs 22.1.3.4)
     return value
+# _T_ is a gramps-defined keyword -- see po/update_po.py and po/genpot.sh
 
 RECORDS = [
     (_T_("Youngest living person"),          'person_youngestliving',   True),
@@ -96,6 +97,7 @@ def find_records(db, filter, top_size, callname,
     """
     @param trans_text: allow deferred translation of strings
     @type trans_text: a GrampsLocale sgettext instance
+    trans_text is a defined keyword (see po/update_po.py, po/genpot.sh)
     """
 
     today = datetime.date.today()
diff --git a/gramps/plugins/textreport/birthdayreport.py b/gramps/plugins/textreport/birthdayreport.py
index 90a535e20..1bef0f45b 100644
--- a/gramps/plugins/textreport/birthdayreport.py
+++ b/gramps/plugins/textreport/birthdayreport.py
@@ -61,6 +61,7 @@ import gramps.plugins.lib.libholiday as libholiday
 
 def _T_(value): # enable deferred translations (see Python docs 22.1.3.4)
     return value
+# _T_ is a gramps-defined keyword -- see po/update_po.py and po/genpot.sh
 
 _TITLE0 = _T_("Birthday and Anniversary Report")
 _TITLE1 = _T_("My Birthday Report")
diff --git a/gramps/plugins/textreport/indivcomplete.py b/gramps/plugins/textreport/indivcomplete.py
index 8dcae8cac..b1f7d3873 100644
--- a/gramps/plugins/textreport/indivcomplete.py
+++ b/gramps/plugins/textreport/indivcomplete.py
@@ -68,6 +68,7 @@ from gramps.gen.utils.file import media_path_full
 
 def _T_(value): # enable deferred translations (see Python docs 22.1.3.4)
     return value
+# _T_ is a gramps-defined keyword -- see po/update_po.py and po/genpot.sh
 
 SECTION_CATEGORY = _("Sections") # only used in add_menu_options (so no _T_)
 # headers for the sections