diff --git a/src/lib/abstracthighlighter.h b/src/lib/abstracthighlighter.h
--- a/src/lib/abstracthighlighter.h
+++ b/src/lib/abstracthighlighter.h
@@ -75,6 +75,7 @@
  * notified whenever the Definition or the Theme changes.
  *
  * @see SyntaxHighlighter
+ * @since 5.28
  */
 class KSYNTAXHIGHLIGHTING_EXPORT AbstractHighlighter
 {
diff --git a/src/lib/definition.h b/src/lib/definition.h
--- a/src/lib/definition.h
+++ b/src/lib/definition.h
@@ -63,6 +63,7 @@
  * with higher priority() wins.
  *
  * @see Repository
+ * @since 5.28
  */
 class KSYNTAXHIGHLIGHTING_EXPORT Definition
 {
diff --git a/src/lib/definitiondownloader.h b/src/lib/definitiondownloader.h
--- a/src/lib/definitiondownloader.h
+++ b/src/lib/definitiondownloader.h
@@ -52,6 +52,7 @@
  * @endcode
  *
  * @see Repository, Definition
+ * @since 5.28
  */
 class KSYNTAXHIGHLIGHTING_EXPORT DefinitionDownloader : public QObject
 {
diff --git a/src/lib/foldingregion.h b/src/lib/foldingregion.h
--- a/src/lib/foldingregion.h
+++ b/src/lib/foldingregion.h
@@ -24,7 +24,8 @@
 
 namespace KSyntaxHighlighting {
 
-/** Represents a begin or end of a folding region. */
+/** Represents a begin or end of a folding region.
+ *  @since 5.28 */
 class KSYNTAXHIGHLIGHTING_EXPORT FoldingRegion
 {
 public:
diff --git a/src/lib/format.h b/src/lib/format.h
--- a/src/lib/format.h
+++ b/src/lib/format.h
@@ -38,6 +38,7 @@
  *  in the syntax definition file, and a theme.
  *
  *  @see Theme
+ *  @since 5.28
  */
 class KSYNTAXHIGHLIGHTING_EXPORT Format
 {
diff --git a/src/lib/repository.h b/src/lib/repository.h
--- a/src/lib/repository.h
+++ b/src/lib/repository.h
@@ -70,6 +70,7 @@
  * either a light or a black color theme.
  *
  * @see Definition, Theme, AbstractHighlighter
+ * @since 5.28
  */
 class KSYNTAXHIGHLIGHTING_EXPORT Repository
 {
diff --git a/src/lib/state.h b/src/lib/state.h
--- a/src/lib/state.h
+++ b/src/lib/state.h
@@ -31,6 +31,8 @@
  *  This needs to be fed into AbstractHighlighter for every line of text
  *  and allows concrete highlighter implementations to store state per
  *  line for fast re-highlighting of specific lines (e.g. during editing).
+ *
+ *  @since 5.28
  */
 class KSYNTAXHIGHLIGHTING_EXPORT State
 {
diff --git a/src/lib/syntaxhighlighter.h b/src/lib/syntaxhighlighter.h
--- a/src/lib/syntaxhighlighter.h
+++ b/src/lib/syntaxhighlighter.h
@@ -31,6 +31,8 @@
 /** A QSyntaxHighlighter implementation for use with QTextDocument.
  *  This supports partial re-highlighting during editing and
  *  tracks syntax-based code folding regions.
+ *
+ *  @since 5.28
  */
 class KSYNTAXHIGHLIGHTING_EXPORT SyntaxHighlighter : public QSyntaxHighlighter, public AbstractHighlighter
 {
diff --git a/src/lib/theme.h b/src/lib/theme.h
--- a/src/lib/theme.h
+++ b/src/lib/theme.h
@@ -70,6 +70,7 @@
  * and therefore unusable.
  *
  * @see Format
+ * @since 5.28
  */
 class KSYNTAXHIGHLIGHTING_EXPORT Theme
 {