diff --git a/packages/block-library/src/comments/edit/comments-inspector-controls.js b/packages/block-library/src/comments/edit/comments-inspector-controls.js
index e548fece552f9d..263e8bde699170 100644
--- a/packages/block-library/src/comments/edit/comments-inspector-controls.js
+++ b/packages/block-library/src/comments/edit/comments-inspector-controls.js
@@ -6,9 +6,17 @@ import { __ } from '@wordpress/i18n';
 import { InspectorControls } from '@wordpress/block-editor';
 
 export default function CommentsInspectorControls( {
-	attributes: { TagName },
+	attributes: { tagName },
 	setAttributes,
 } ) {
+	const htmlElementMessages = {
+		section: __(
+			"The <section> element should represent a standalone portion of the document that can't be better represented by another element."
+		),
+		aside: __(
+			"The <aside> element should represent a portion of a document whose content is only indirectly related to the document's main content."
+		),
+	};
 	return (
 		<InspectorControls>
 			<InspectorControls __experimentalGroup="advanced">
@@ -20,10 +28,11 @@ export default function CommentsInspectorControls( {
 						{ label: '<section>', value: 'section' },
 						{ label: '<aside>', value: 'aside' },
 					] }
-					value={ TagName }
+					value={ tagName }
 					onChange={ ( value ) =>
 						setAttributes( { tagName: value } )
 					}
+					help={ htmlElementMessages[ tagName ] }
 				/>
 			</InspectorControls>
 		</InspectorControls>
diff --git a/packages/block-library/src/query/edit/query-content.js b/packages/block-library/src/query/edit/query-content.js
index a66a5c75f18411..193499709d0689 100644
--- a/packages/block-library/src/query/edit/query-content.js
+++ b/packages/block-library/src/query/edit/query-content.js
@@ -94,6 +94,17 @@ export default function QueryContent( {
 		setAttributes( {
 			displayLayout: { ...displayLayout, ...newDisplayLayout },
 		} );
+	const htmlElementMessages = {
+		main: __(
+			'The <main> element should be used for the primary content of your document only. '
+		),
+		section: __(
+			"The <section> element should represent a standalone portion of the document that can't be better represented by another element."
+		),
+		aside: __(
+			"The <aside> element should represent a portion of a document whose content is only indirectly related to the document's main content."
+		),
+	};
 	return (
 		<>
 			<QueryInspectorControls
@@ -125,6 +136,7 @@ export default function QueryContent( {
 					onChange={ ( value ) =>
 						setAttributes( { tagName: value } )
 					}
+					help={ htmlElementMessages[ TagName ] }
 				/>
 			</InspectorControls>
 			<TagName { ...innerBlocksProps } />
diff --git a/packages/block-library/src/template-part/edit/advanced-controls.js b/packages/block-library/src/template-part/edit/advanced-controls.js
index 1ef81748d7742a..7683615738daf0 100644
--- a/packages/block-library/src/template-part/edit/advanced-controls.js
+++ b/packages/block-library/src/template-part/edit/advanced-controls.js
@@ -49,6 +49,27 @@ export function TemplatePartAdvancedControls( {
 		};
 	}, [] );
 
+	const htmlElementMessages = {
+		header: __(
+			'The <header> element should represent introductory content, typically a group of introductory or navigational aids.'
+		),
+		main: __(
+			'The <main> element should be used for the primary content of your document only. '
+		),
+		section: __(
+			"The <section> element should represent a standalone portion of the document that can't be better represented by another element."
+		),
+		article: __(
+			'The <article> element should represent a self-contained, syndicatable portion of the document.'
+		),
+		aside: __(
+			"The <aside> element should represent a portion of a document whose content is only indirectly related to the document's main content."
+		),
+		footer: __(
+			'The <footer> element should represent a footer for its nearest sectioning element (e.g.: <section>, <article>, <main> etc.).'
+		),
+	};
+
 	return (
 		<InspectorControls __experimentalGroup="advanced">
 			{ isEntityAvailable && (
@@ -94,6 +115,7 @@ export function TemplatePartAdvancedControls( {
 				] }
 				value={ tagName || '' }
 				onChange={ ( value ) => setAttributes( { tagName: value } ) }
+				help={ htmlElementMessages[ tagName ] }
 			/>
 			{ ! hasInnerBlocks && (
 				<TemplatePartImportControls