diff --git a/packages/block-editor/src/store/private-selectors.js b/packages/block-editor/src/store/private-selectors.js
index d76f90bc94ffe..01ad8f69febc9 100644
--- a/packages/block-editor/src/store/private-selectors.js
+++ b/packages/block-editor/src/store/private-selectors.js
@@ -548,6 +548,15 @@ export function isZoomOutMode( state ) {
 	return state.editorMode === 'zoom-out';
 }
 
+/**
+ * Retrieves the client ID of the block which contains the blocks
+ * acting as "sections" in the editor. This is typically the "main content"
+ * of the template/post.
+ *
+ * @param {Object} state Editor state.
+ *
+ * @return {string|undefined} The section root client ID or undefined if not set.
+ */
 export function getSectionRootClientId( state ) {
 	return state.settings?.[ sectionRootClientIdKey ];
 }