diff --git a/vncviewer/vncviewer.cxx b/vncviewer/vncviewer.cxx
index cf52de5..bf4bfb1 100644
--- a/vncviewer/vncviewer.cxx
+++ b/vncviewer/vncviewer.cxx
@@ -460,6 +460,8 @@
 #ifndef WIN32
   /* Specifying -via and -listen together is nonsense */
   if (listenMode && strlen(via.getValueStr()) > 0) {
+    // TRANSLATORS: "Parameters" are command line arguments, or settings
+    // from a file or the Windows registry.
     vlog.error(_("Parameters -listen and -via are incompatible"));
     fl_alert(_("Parameters -listen and -via are incompatible"));
     exit_vncviewer();