--- a/libgui/languages/build_ts/README.md	Tue Dec 05 14:15:58 2023 -0500
+++ b/libgui/languages/build_ts/README.md	Wed Dec 06 14:55:08 2023 -0500
@@ -4,7 +4,7 @@
 
 Before a new release of Octave, the language files  `libgui/languages/*.ts` have to be updated with changed or new strings in the source files in order to add translations afterwards.
 
-## How to update the files
+## How to update the files (*.ts)
 
  The update is carried out by the Qt-tool `lupdate` which collect strings in source files found in the search path(s) provided as input argument to `lupdate`. The tool `lupdate`is called from the script
 
@@ -12,10 +12,33 @@
 
 which also determines the required search paths for each language.
 
-Besides source folders within `libgui`, the search path is extended by some qt and qsci files, collected in `libgui/build_ts/octave-qt` and `libgui/build_ts/octave-qsci` respectively, whenever there are no translation files for the language from Qt or QsciScintilla.
+Besides source folders within `libgui`, the search path is extended by some Qt and Qsci files, collected in
+
+- `libgui/build_ts/octave-qt` and
+- `libgui/build_ts/octave-qsci`
+
+respectively, whenever there are no translation files for the language from Qt or QScintilla.
 
 The Following steps are required in order to update the language files `libgui/languages/*.ts`:
 
 1. Change into `libgui/languages`
 2. Start the update by calling `build_ts/update_ts_files`
 3. Select the language files that should be updated
+
+## Updating Qt and Qsci used for the language files
+
+From time to time, like, e.g., when a new major version of Qt is available, the source files in
+
+- `libgui/build_ts/octave-qt` and
+- `libgui/build_ts/octave-qsci`
+
+should also be updated. These source are scanned for strings for language where no translation is provided by Qt and/or QScintilla. The sources are update with the following steps:
+
+1. Download the Qt sources (example for Qt6):
+    1. `$ git clone git://code.qt.io/qt/qt5.git qt6`
+    2. `$ cd qt6`
+    3. `$ git switch 6.6`
+    4. `$ perl init-repository`
+2. [Download the latest QScintilla](https://riverbankcomputing.com/software/qscintilla/download) and unpack he archive to the desired location
+3. Change into `libgui/languages/build_ts`
+4. Call `./update_external_sources  path_qt  path_qsci` where `path_qt` and `path_qsci` are the absolute or relative paths to the Qt and QScintilla sources respectively.