diff --git a/demos/gtk-demo/assistant.c b/demos/gtk-demo/assistant.c
index 58405f6cc9..a84b87ad81 100644
--- a/demos/gtk-demo/assistant.c
+++ b/demos/gtk-demo/assistant.c
@@ -1,8 +1,8 @@
 /* Assistant
  *
- * Demonstrates a sample multi-step assistant. Assistants are used to divide
- * an operation into several simpler sequential steps, and to guide the user
- * through these steps.
+ * Demonstrates a sample multi-step assistant with GtkAssistant. Assistants
+ * are used to divide an operation into several simpler sequential steps,
+ * and to guide the user through these steps.
  */
 
 #include <gtk/gtk.h>
diff --git a/demos/gtk-demo/combobox.c b/demos/gtk-demo/combobox.c
index 0686eaf59b..d7a7320eb0 100644
--- a/demos/gtk-demo/combobox.c
+++ b/demos/gtk-demo/combobox.c
@@ -1,4 +1,5 @@
 /* Combo Boxes
+ * #Keywords: GtkCellRenderer
  *
  * The GtkComboBox widget allows to select one option out of a list.
  * The GtkComboBoxEntry additionally allows the user to enter a value
diff --git a/demos/gtk-demo/constraints.c b/demos/gtk-demo/constraints.c
index 6f842008fb..2e31f22462 100644
--- a/demos/gtk-demo/constraints.c
+++ b/demos/gtk-demo/constraints.c
@@ -1,4 +1,5 @@
 /* Constraints/Simple
+ * #Keywords: GtkLayoutManager
  *
  * GtkConstraintLayout provides a layout manager that uses relations
  * between widgets (also known as "constraints") to compute the position
diff --git a/demos/gtk-demo/constraints2.c b/demos/gtk-demo/constraints2.c
index 8e804592ed..d63b369739 100644
--- a/demos/gtk-demo/constraints2.c
+++ b/demos/gtk-demo/constraints2.c
@@ -1,4 +1,5 @@
 /* Constraints/Interactive
+ * #Keywords: GtkConstraintLayout
  *
  * Demonstrate how constraints can be updates during user interaction.
  * The vertical edge between the buttons can be dragged with the mouse.
diff --git a/demos/gtk-demo/css_accordion.c b/demos/gtk-demo/css_accordion.c
index 45e3538803..c544f8a02d 100644
--- a/demos/gtk-demo/css_accordion.c
+++ b/demos/gtk-demo/css_accordion.c
@@ -1,7 +1,6 @@
 /* Theming/CSS Accordion
  *
  * A simple accordion demo written using CSS transitions and multiple backgrounds
- *
  */
 
 #include <gtk/gtk.h>
diff --git a/demos/gtk-demo/css_basics.c b/demos/gtk-demo/css_basics.c
index bb193d62ef..1c9f309800 100644
--- a/demos/gtk-demo/css_basics.c
+++ b/demos/gtk-demo/css_basics.c
@@ -1,8 +1,7 @@
 /* Theming/CSS Basics
  *
- * Gtk themes are written using CSS. Every widget is build of multiple items
+ * GTK themes are written using CSS. Every widget is build of multiple items
  * that you can style very similarly to a regular website.
- *
  */
 
 #include <gtk/gtk.h>
diff --git a/demos/gtk-demo/css_multiplebgs.c b/demos/gtk-demo/css_multiplebgs.c
index dd11c2ddbf..b3badee669 100644
--- a/demos/gtk-demo/css_multiplebgs.c
+++ b/demos/gtk-demo/css_multiplebgs.c
@@ -1,8 +1,7 @@
 /* Theming/Multiple Backgrounds
  *
- * Gtk themes are written using CSS. Every widget is build of multiple items
+ * GTK themes are written using CSS. Every widget is build of multiple items
  * that you can style very similarly to a regular website.
- *
  */
 
 #include <gtk/gtk.h>
diff --git a/demos/gtk-demo/dialog.c b/demos/gtk-demo/dialog.c
index 91b1bfa8bb..3b355fef3e 100644
--- a/demos/gtk-demo/dialog.c
+++ b/demos/gtk-demo/dialog.c
@@ -1,4 +1,5 @@
 /* Dialogs
+ * #Keywords: GtkMessageDialog
  *
  * Dialogs are used to pop up transient windows for information
  * and user feedback.
diff --git a/demos/gtk-demo/drawingarea.c b/demos/gtk-demo/drawingarea.c
index f7b567d382..14b87f64d3 100644
--- a/demos/gtk-demo/drawingarea.c
+++ b/demos/gtk-demo/drawingarea.c
@@ -1,4 +1,5 @@
 /* Drawing Area
+ * #Keywords: GtkDrawingArea
  *
  * GtkDrawingArea is a blank area where you can draw custom displays
  * of various kinds.
diff --git a/demos/gtk-demo/filtermodel.c b/demos/gtk-demo/filtermodel.c
index 85180372ee..b4f07337b1 100644
--- a/demos/gtk-demo/filtermodel.c
+++ b/demos/gtk-demo/filtermodel.c
@@ -1,4 +1,5 @@
 /* Tree View/Filter Model
+ * #Keywords: GtkTreeView
  *
  * This example demonstrates how GtkTreeModelFilter can be used not
  * just to show a subset of the rows, but also to compute columns
diff --git a/demos/gtk-demo/fixed.c b/demos/gtk-demo/fixed.c
index b9a140df4a..f539e53e9b 100644
--- a/demos/gtk-demo/fixed.c
+++ b/demos/gtk-demo/fixed.c
@@ -1,4 +1,5 @@
 /* Fixed Layout
+ * #Keywords: GtkLayoutManager
  *
  * GtkFixed is a container that allows placing and transforming
  * widgets manually.
diff --git a/demos/gtk-demo/gestures.c b/demos/gtk-demo/gestures.c
index 690d4ea355..d6682db9a4 100644
--- a/demos/gtk-demo/gestures.c
+++ b/demos/gtk-demo/gestures.c
@@ -1,4 +1,5 @@
 /* Gestures
+ * #Keywords: GtkGesture
  *
  * Perform gestures on touchscreens and other input devices. This
  * demo reacts to long presses and swipes from all devices, plus
diff --git a/demos/gtk-demo/headerbar.c b/demos/gtk-demo/headerbar.c
index 2783f08a8d..f5e81fca89 100644
--- a/demos/gtk-demo/headerbar.c
+++ b/demos/gtk-demo/headerbar.c
@@ -1,4 +1,5 @@
 /* Header Bar
+ * #Keywords: GtkWindowHandle, GtkWindowControls
  *
  * GtkHeaderBar is a container that is suitable for implementing
  * window titlebars. One of its features is that it can position
diff --git a/demos/gtk-demo/hypertext.c b/demos/gtk-demo/hypertext.c
index 95c5a3ea31..9236d188a5 100644
--- a/demos/gtk-demo/hypertext.c
+++ b/demos/gtk-demo/hypertext.c
@@ -1,4 +1,5 @@
 /* Text View/Hypertext
+ * #Keywords: GtkTextView, GtkTextBuffer
  *
  * Usually, tags modify the appearance of text in the view, e.g. making it
  * bold or colored or underlined. But tags are not restricted to appearance.
diff --git a/demos/gtk-demo/iconscroll.c b/demos/gtk-demo/iconscroll.c
index 9c9e198e2c..3c05e2755d 100644
--- a/demos/gtk-demo/iconscroll.c
+++ b/demos/gtk-demo/iconscroll.c
@@ -1,4 +1,5 @@
 /* Benchmark/Scrolling
+ * #Keywords: GtkScrolledWindow
  *
  * This demo scrolls a view with various content.
  */
diff --git a/demos/gtk-demo/images.c b/demos/gtk-demo/images.c
index c53bd5f688..43d138101c 100644
--- a/demos/gtk-demo/images.c
+++ b/demos/gtk-demo/images.c
@@ -1,4 +1,5 @@
 /* Images
+ * #Keywords: GdkPaintable, GtkWidgetPaintable
  *
  * GtkImage and GtkPicture are used to display an image; the image can be
  * in a number of formats.
diff --git a/demos/gtk-demo/infobar.c b/demos/gtk-demo/infobar.c
index 32f88c8eb8..15caf10286 100644
--- a/demos/gtk-demo/infobar.c
+++ b/demos/gtk-demo/infobar.c
@@ -1,4 +1,5 @@
 /* Info Bars
+ * #Keywords: GtkInfoBar
  *
  * Info bar widgets are used to report important messages to the user.
  */
diff --git a/demos/gtk-demo/layoutmanager.c b/demos/gtk-demo/layoutmanager.c
index b07c453798..b03bc040a1 100644
--- a/demos/gtk-demo/layoutmanager.c
+++ b/demos/gtk-demo/layoutmanager.c
@@ -1,4 +1,5 @@
 /* Layout Manager/Transition
+ * #Keywords: GtkLayoutManager
  *
  * This demo shows a simple example of a custom layout manager
  * and a widget using it. The layout manager places the children
diff --git a/demos/gtk-demo/layoutmanager2.c b/demos/gtk-demo/layoutmanager2.c
index 8d17f2a47d..83691c3dfe 100644
--- a/demos/gtk-demo/layoutmanager2.c
+++ b/demos/gtk-demo/layoutmanager2.c
@@ -1,4 +1,5 @@
 /* Layout Manager/Transformation
+ * #Keywords: GtkLayoutManager, GskTransform
  *
  * This demo shows how to use transforms in a nontrivial
  * way with a custom layout manager. The layout manager places
diff --git a/demos/gtk-demo/list_store.c b/demos/gtk-demo/list_store.c
index 1ca6bff2d1..7619a51a68 100644
--- a/demos/gtk-demo/list_store.c
+++ b/demos/gtk-demo/list_store.c
@@ -3,7 +3,6 @@
  * The GtkListStore is used to store data in list form, to be used
  * later on by a GtkTreeView to display it. This demo builds a
  * simple GtkListStore and displays it.
- *
  */
 
 #include <gtk/gtk.h>
diff --git a/demos/gtk-demo/listbox.c b/demos/gtk-demo/listbox.c
index 0a9b6959df..4905fecd79 100644
--- a/demos/gtk-demo/listbox.c
+++ b/demos/gtk-demo/listbox.c
@@ -2,7 +2,6 @@
  *
  * GtkListBox allows lists with complicated layouts, using
  * regular widgets supporting sorting and filtering.
- *
  */
 
 #include <gtk/gtk.h>
diff --git a/demos/gtk-demo/listview_applauncher.c b/demos/gtk-demo/listview_applauncher.c
index 3dcdbca055..15f5e32a96 100644
--- a/demos/gtk-demo/listview_applauncher.c
+++ b/demos/gtk-demo/listview_applauncher.c
@@ -1,4 +1,5 @@
 /* Lists/Application launcher
+ * #Keywords: GtkListItemFactory, GListModel
  *
  * This demo uses the GtkListView widget as a fancy application launcher.
  *
diff --git a/demos/gtk-demo/listview_clocks.c b/demos/gtk-demo/listview_clocks.c
index 9dbdc0d5e7..22a463823d 100644
--- a/demos/gtk-demo/listview_clocks.c
+++ b/demos/gtk-demo/listview_clocks.c
@@ -1,10 +1,11 @@
 /* Lists/Clocks
+ * #Keywords: GtkGridView, GtkListItemFactory, GListModel
  *
  * This demo displays the time in different timezones.
  *
  * The goal is to show how to set up expressions that track changes
  * in objects and make them update widgets. For that, we create a
- * GtkClock object that updates its time every second and then use
+ * clock object that updates its time every second and then use
  * various ways to display that time.
  *
  * Typically, this will be done using GtkBuilder .ui files with the
diff --git a/demos/gtk-demo/listview_colors.c b/demos/gtk-demo/listview_colors.c
index aa4cdf1468..c05807a1c1 100644
--- a/demos/gtk-demo/listview_colors.c
+++ b/demos/gtk-demo/listview_colors.c
@@ -1,4 +1,5 @@
 /* Lists/Colors
+ * #Keywords: GtkSortListModel, GtkMultiSelection
  *
  * This demo displays a grid of colors.
  *
diff --git a/demos/gtk-demo/listview_filebrowser.c b/demos/gtk-demo/listview_filebrowser.c
index 47237cb3c7..a840950ee8 100644
--- a/demos/gtk-demo/listview_filebrowser.c
+++ b/demos/gtk-demo/listview_filebrowser.c
@@ -1,4 +1,5 @@
 /* Lists/File browser
+ * #Keywords: GListModel
  *
  * This demo shows off the different layouts that are quickly achievable
  * with GtkListview and GtkGridView by implementing a file browser with
diff --git a/demos/gtk-demo/listview_minesweeper.c b/demos/gtk-demo/listview_minesweeper.c
index e43eaceb0b..11ad0759be 100644
--- a/demos/gtk-demo/listview_minesweeper.c
+++ b/demos/gtk-demo/listview_minesweeper.c
@@ -1,7 +1,8 @@
 /* Lists/Minesweeper
+ * #Keywords: GtkGridView, GListModel, game
  *
  * This demo shows how to develop a user interface for small game using a
- * gridview.
+ * grid view.
  *
  * It demonstrates how to use the activate signal and single-press behavior
  * to implement rather different interaction behavior to a typical list.
diff --git a/demos/gtk-demo/listview_settings.c b/demos/gtk-demo/listview_settings.c
index 57e4797c1a..6e67d56790 100644
--- a/demos/gtk-demo/listview_settings.c
+++ b/demos/gtk-demo/listview_settings.c
@@ -1,4 +1,5 @@
 /* Lists/Settings
+ * #Keywords: GtkListItemFactory, GListModel
  *
  * This demo shows a settings viewer for GSettings.
  *
diff --git a/demos/gtk-demo/listview_words.c b/demos/gtk-demo/listview_words.c
index 4aa9a9977c..867f74e652 100644
--- a/demos/gtk-demo/listview_words.c
+++ b/demos/gtk-demo/listview_words.c
@@ -1,4 +1,5 @@
 /* Lists/Words
+ * #Keywords: GtkListView, GtkFilterListModel
  *
  * This demo shows filtering a long list - of words.
  *
diff --git a/demos/gtk-demo/markup.c b/demos/gtk-demo/markup.c
index 6648d508f3..900436f6e7 100644
--- a/demos/gtk-demo/markup.c
+++ b/demos/gtk-demo/markup.c
@@ -1,4 +1,5 @@
 /* Text View/Markup
+ * #Keywords: GtkTextView
  *
  * GtkTextBuffer lets you define your own tags that can influence
  * text formatting in a variety of ways. In this example, we show
diff --git a/demos/gtk-demo/overlay.c b/demos/gtk-demo/overlay.c
index e56d6fe36e..51d09bcb24 100644
--- a/demos/gtk-demo/overlay.c
+++ b/demos/gtk-demo/overlay.c
@@ -1,4 +1,5 @@
 /* Overlay/Interactive Overlay
+ * #Keywords: GtkOverlay
  *
  * Shows widgets in static positions over a main widget.
  *
diff --git a/demos/gtk-demo/overlay2.c b/demos/gtk-demo/overlay2.c
index 10b4476fb2..11f2e2a243 100644
--- a/demos/gtk-demo/overlay2.c
+++ b/demos/gtk-demo/overlay2.c
@@ -1,4 +1,5 @@
 /* Overlay/Decorative Overlay
+ * #Keywords: GtkOverlay
  *
  * Another example of an overlay with some decorative
  * and some interactive controls.
diff --git a/demos/gtk-demo/pagesetup.c b/demos/gtk-demo/pagesetup.c
index 09150a9eb7..1f58652b6e 100644
--- a/demos/gtk-demo/pagesetup.c
+++ b/demos/gtk-demo/pagesetup.c
@@ -1,4 +1,5 @@
 /* Printing/Page Setup
+ * #Keywords: GtkPageSetup
  *
  * GtkPageSetupUnixDialog can be used if page setup is needed
  * independent of a full printing dialog.
diff --git a/demos/gtk-demo/paint.c b/demos/gtk-demo/paint.c
index e95e25a5a1..147ddea753 100644
--- a/demos/gtk-demo/paint.c
+++ b/demos/gtk-demo/paint.c
@@ -1,4 +1,5 @@
 /* Paint
+ * #Keywords: GdkDrawingArea, GtkGesture
  *
  * Demonstrates practical handling of drawing tablets in a real world
  * usecase.
diff --git a/demos/gtk-demo/peg_solitaire.c b/demos/gtk-demo/peg_solitaire.c
index 70681c1f57..4fe4f11d44 100644
--- a/demos/gtk-demo/peg_solitaire.c
+++ b/demos/gtk-demo/peg_solitaire.c
@@ -1,4 +1,5 @@
 /* Peg Solitaire
+ * #Keywords: GtkGridView, game
  *
  * This demo demonstrates how to use drag'n'drop to implement peg solitaire.
  *
diff --git a/demos/gtk-demo/pickers.c b/demos/gtk-demo/pickers.c
index a5404d1e79..6a4da706e2 100644
--- a/demos/gtk-demo/pickers.c
+++ b/demos/gtk-demo/pickers.c
@@ -1,4 +1,6 @@
 /* Pickers
+ * #Keywords: GtkColorChooser, GtkFontChooser, GtkFileChooser,
+ * #Keywords: GtkApplicationChooser
  *
  * These widgets are mainly intended for use in preference dialogs.
  * They allow to select colors, fonts, files, directories and applications.
diff --git a/demos/gtk-demo/printing.c b/demos/gtk-demo/printing.c
index f095c59575..beef569f25 100644
--- a/demos/gtk-demo/printing.c
+++ b/demos/gtk-demo/printing.c
@@ -2,7 +2,6 @@
  *
  * GtkPrintOperation offers a simple API to support printing
  * in a cross-platform way.
- *
  */
 
 #include <math.h>
diff --git a/demos/gtk-demo/rotated_text.c b/demos/gtk-demo/rotated_text.c
index 88a81edaa8..4f2c3f9513 100644
--- a/demos/gtk-demo/rotated_text.c
+++ b/demos/gtk-demo/rotated_text.c
@@ -1,10 +1,10 @@
 /* Pango/Rotated Text
  *
  * This demo shows how to use PangoCairo to draw rotated and transformed
- * text.  The right pane shows a rotated GtkLabel widget.
+ * text. The right pane shows a rotated GtkLabel widget.
  *
  * In both cases, a custom PangoCairo shape renderer is installed to draw
- * a red heard using cairo drawing operations instead of the Unicode heart
+ * a red heart using cairo drawing operations instead of the Unicode heart
  * character.
  */
 
diff --git a/demos/gtk-demo/search_entry2.c b/demos/gtk-demo/search_entry2.c
index 29d417adf1..f6027196b7 100644
--- a/demos/gtk-demo/search_entry2.c
+++ b/demos/gtk-demo/search_entry2.c
@@ -1,9 +1,13 @@
 /* Entry/Delayed Search Entry
  *
- * GtkSearchEntry sets up GtkEntries ready for search. Search entries
- * have their "changed" signal delayed and should be used
- * when the searched operation is slow such as loads of entries
- * to search, or online searches.
+ * GtkSearchEntry provides an entry that is ready for search.
+ *
+ * Search entries have their "changed" signal delayed and should
+ * be used when the searched operation is slow such as loads of
+ * entries to search, or online searches.
+ *
+ * GtkSearchBar allows have a hidden search entry that 'springs
+ * into action' upon keyboard input.
  */
 
 #include <gtk/gtk.h>
diff --git a/demos/gtk-demo/shadertoy.c b/demos/gtk-demo/shadertoy.c
index cd8ba2bb41..2831baf51b 100644
--- a/demos/gtk-demo/shadertoy.c
+++ b/demos/gtk-demo/shadertoy.c
@@ -1,4 +1,5 @@
 /* OpenGL/Shadertoy
+ * #Keywords: GtkGLArea
  *
  * Generate pixels using a custom fragment shader.
  *
diff --git a/demos/gtk-demo/shortcut_triggers.c b/demos/gtk-demo/shortcut_triggers.c
index b84cb0354c..44b8839ca7 100644
--- a/demos/gtk-demo/shortcut_triggers.c
+++ b/demos/gtk-demo/shortcut_triggers.c
@@ -1,4 +1,5 @@
 /* Shortcuts
+ * #Keywords: GtkShortcutController
  *
  * GtkShortcut is the abstraction used by GTK to handle shortcuts from
  * keyboard or other input devices.
diff --git a/demos/gtk-demo/sliding_puzzle.c b/demos/gtk-demo/sliding_puzzle.c
index a91aa6c227..4d7e23f908 100644
--- a/demos/gtk-demo/sliding_puzzle.c
+++ b/demos/gtk-demo/sliding_puzzle.c
@@ -1,8 +1,8 @@
 /* Sliding Puzzle
+ * #Keywords: GdkPaintable, GdkGesture, game
  *
  * This demo demonstrates how to use gestures and paintables to create a
  * small sliding puzzle game.
- *
  */
 
 #include <gtk/gtk.h>
diff --git a/demos/gtk-demo/spinbutton.c b/demos/gtk-demo/spinbutton.c
index 97f25b857a..fda257af17 100644
--- a/demos/gtk-demo/spinbutton.c
+++ b/demos/gtk-demo/spinbutton.c
@@ -1,4 +1,5 @@
 /* Spin Buttons
+ * #Keywords: GtkEntry
  *
  * GtkSpinButton provides convenient ways to input data
  * that can be seen as a value in a range. The examples
diff --git a/demos/gtk-demo/spinner.c b/demos/gtk-demo/spinner.c
index 21c33441e9..925f02576e 100644
--- a/demos/gtk-demo/spinner.c
+++ b/demos/gtk-demo/spinner.c
@@ -1,7 +1,6 @@
 /* Spinner
  *
  * GtkSpinner allows to show that background activity is on-going.
- *
  */
 
 #include <glib/gi18n.h>
diff --git a/demos/gtk-demo/textscroll.c b/demos/gtk-demo/textscroll.c
index 338bb8b3cf..8bb62a8406 100644
--- a/demos/gtk-demo/textscroll.c
+++ b/demos/gtk-demo/textscroll.c
@@ -1,4 +1,5 @@
 /* Text View/Automatic Scrolling
+ * #Keywords: GtkTextView, GtkScrolledWindow
  *
  * This example demonstrates how to use the gravity of
  * GtkTextMarks to keep a text view scrolled to the bottom
diff --git a/demos/gtk-demo/transparent.c b/demos/gtk-demo/transparent.c
index 263806e814..7263feb718 100644
--- a/demos/gtk-demo/transparent.c
+++ b/demos/gtk-demo/transparent.c
@@ -1,4 +1,5 @@
 /* Overlay/Transparency
+ * #Keywords: GtkOverlay, GtkSnapshot
  *
  * Blur the background behind an overlay.
  */
diff --git a/demos/gtk-demo/video_player.c b/demos/gtk-demo/video_player.c
index f417870549..d2df677a5d 100644
--- a/demos/gtk-demo/video_player.c
+++ b/demos/gtk-demo/video_player.c
@@ -1,4 +1,6 @@
 /* Video Player
+ * #Keywords: GtkVideo, GtkMediaStream, GtkMediaFile, GdkPaintable
+ * #Keywords: GtkMediaControls
  *
  * This is a simple video player using just GTK widgets.
  */