HTML • Chapter 57 • Foundations to Production
Obsolete and Risky HTML
Each topic contains substantial explanation, ten focused teaching examples, its own HTML code example, code reasoning, expected browser result, and practice.
57.1 Obsolete Presentational Elements
Obsolete Presentational Elements is part of the HTML structure covered in Chapter 57. HTML communicates meaning and document relationships to browsers, search engines, assistive technology, and other tools, so the choice of element or attribute should match the content rather than only its visual appearance.
For Obsolete Presentational Elements, examine the element's permitted content, relevant attributes, semantic meaning, accessibility effect, and how it behaves when CSS or JavaScript is unavailable. In obsolete and risky html, the markup should remain understandable as a document before presentation is added.
In Chapter 57, a reliable way to learn Obsolete Presentational Elements is to write a small valid fragment, inspect the browser result and document outline, then test one incorrect or missing attribute. This makes the reason for each piece of markup visible instead of treating HTML as a collection of tags to memorize.
Concept in plain language
Obsolete Presentational Elements is part of the HTML structure covered in Chapter 57. HTML communicates meaning and document relationships to browsers, search engines, assistive technology, and other tools, so the choice of element or attribute should match the content rather than only its visual appearance.
10 teaching examples
Example 1: Minimal markup
Create the smallest valid documentation page example that demonstrates Obsolete Presentational Elements. Identify which part carries meaning and which parts are only supporting structure. This is Chapter 57, topic 1, example 1.
Example 2: Content variation
Change the text or resource used by Obsolete Presentational Elements in the event page. Confirm that the markup still describes the new content correctly instead of depending on the old wording. This is Chapter 57, topic 1, example 2.
Example 3: Missing-information test
Remove one important attribute or related element from the FAQ page example using Obsolete Presentational Elements. Explain what meaning, accessibility, navigation, or browser behavior is lost. This is Chapter 57, topic 1, example 3.
Example 4: Accessibility review
Read the photo story example using the semantics of Obsolete Presentational Elements. Check names, labels, landmarks, alternatives, focus behavior, and whether the content still makes sense without styling. This is Chapter 57, topic 1, example 4.
Example 5: Mobile review
Open the support page markup containing Obsolete Presentational Elements on a narrow screen. Ensure embedded content, long text, controls, and translated labels do not force the page wider than the viewport. This is Chapter 57, topic 1, example 5.
Example 6: RTL review
Translate the dashboard shell into Arabic or Persian. Keep document text RTL where appropriate while URLs, code samples, numbers, and intentionally LTR fragments remain readable. This is Chapter 57, topic 1, example 6.
Example 7: Validation exercise
Run the language page fragment using Obsolete Presentational Elements through an HTML validator. Fix invalid nesting, duplicate IDs, missing required attributes, or obsolete markup before adding extra features. This is Chapter 57, topic 1, example 7.
Example 8: Progressive-enhancement check
Use Obsolete Presentational Elements in the booking page so the core content remains useful before CSS and JavaScript load. Add enhancement only after the document structure is complete. This is Chapter 57, topic 1, example 8.
Example 9: SEO and semantics review
Inspect how Obsolete Presentational Elements contributes to the meaning of the media page. Keep headings, links, metadata, and document regions consistent so crawlers and users receive the same primary content. This is Chapter 57, topic 1, example 9.
Example 10: Production review
Review Obsolete Presentational Elements in the school page for validity, accessibility, security-related attributes, performance hints, responsive behavior, localization, and maintainability. This is Chapter 57, topic 1, example 10.
HTML code example
<main>
<h1>Modern semantic page</h1>
<p>Use CSS for presentation instead of obsolete presentational HTML.</p>
</main>Step-by-step code explanation
- Identify the element or attribute responsible for Obsolete Presentational Elements.
- Read the markup from the outer document structure inward and verify that each child is allowed in its parent context.
- Check the semantic meaning and any accessibility relationship such as labels, alternatives, headings, captions, or landmarks.
- Open the fragment in a browser and compare the rendered result with the source instead of assuming visual appearance proves validity.
- Validate the markup and test responsive, RTL, and no-JavaScript behavior where they apply.
Expected browser result: The browser displays or exposes the structure appropriate for Obsolete Presentational Elements while preserving the semantic relationships expressed by the markup.
Practice exercise
Write a fresh HTML fragment for Obsolete Presentational Elements in Chapter 57. Validate it, remove one important attribute or related element to observe the difference, then restore the correct markup. Test the result with keyboard navigation when interactive, on a narrow screen, and in Arabic or Persian when the content can be translated.
57.2 Deprecated Attributes
Deprecated Attributes is part of the HTML structure covered in Chapter 57. HTML communicates meaning and document relationships to browsers, search engines, assistive technology, and other tools, so the choice of element or attribute should match the content rather than only its visual appearance.
For Deprecated Attributes, examine the element's permitted content, relevant attributes, semantic meaning, accessibility effect, and how it behaves when CSS or JavaScript is unavailable. In obsolete and risky html, the markup should remain understandable as a document before presentation is added.
In Chapter 57, a reliable way to learn Deprecated Attributes is to write a small valid fragment, inspect the browser result and document outline, then test one incorrect or missing attribute. This makes the reason for each piece of markup visible instead of treating HTML as a collection of tags to memorize.
Concept in plain language
Deprecated Attributes is part of the HTML structure covered in Chapter 57. HTML communicates meaning and document relationships to browsers, search engines, assistive technology, and other tools, so the choice of element or attribute should match the content rather than only its visual appearance.
10 teaching examples
Example 1: Minimal markup
Create the smallest valid FAQ page example that demonstrates Deprecated Attributes. Identify which part carries meaning and which parts are only supporting structure. This is Chapter 57, topic 2, example 1.
Example 2: Content variation
Change the text or resource used by Deprecated Attributes in the photo story. Confirm that the markup still describes the new content correctly instead of depending on the old wording. This is Chapter 57, topic 2, example 2.
Example 3: Missing-information test
Remove one important attribute or related element from the support page example using Deprecated Attributes. Explain what meaning, accessibility, navigation, or browser behavior is lost. This is Chapter 57, topic 2, example 3.
Example 4: Accessibility review
Read the dashboard shell example using the semantics of Deprecated Attributes. Check names, labels, landmarks, alternatives, focus behavior, and whether the content still makes sense without styling. This is Chapter 57, topic 2, example 4.
Example 5: Mobile review
Open the language page markup containing Deprecated Attributes on a narrow screen. Ensure embedded content, long text, controls, and translated labels do not force the page wider than the viewport. This is Chapter 57, topic 2, example 5.
Example 6: RTL review
Translate the booking page into Arabic or Persian. Keep document text RTL where appropriate while URLs, code samples, numbers, and intentionally LTR fragments remain readable. This is Chapter 57, topic 2, example 6.
Example 7: Validation exercise
Run the media page fragment using Deprecated Attributes through an HTML validator. Fix invalid nesting, duplicate IDs, missing required attributes, or obsolete markup before adding extra features. This is Chapter 57, topic 2, example 7.
Example 8: Progressive-enhancement check
Use Deprecated Attributes in the school page so the core content remains useful before CSS and JavaScript load. Add enhancement only after the document structure is complete. This is Chapter 57, topic 2, example 8.
Example 9: SEO and semantics review
Inspect how Deprecated Attributes contributes to the meaning of the course lesson. Keep headings, links, metadata, and document regions consistent so crawlers and users receive the same primary content. This is Chapter 57, topic 2, example 9.
Example 10: Production review
Review Deprecated Attributes in the news article for validity, accessibility, security-related attributes, performance hints, responsive behavior, localization, and maintainability. This is Chapter 57, topic 2, example 10.
HTML code example
<main>
<h1>Modern semantic page</h1>
<p>Use CSS for presentation instead of obsolete presentational HTML.</p>
</main>Step-by-step code explanation
- Identify the element or attribute responsible for Deprecated Attributes.
- Read the markup from the outer document structure inward and verify that each child is allowed in its parent context.
- Check the semantic meaning and any accessibility relationship such as labels, alternatives, headings, captions, or landmarks.
- Open the fragment in a browser and compare the rendered result with the source instead of assuming visual appearance proves validity.
- Validate the markup and test responsive, RTL, and no-JavaScript behavior where they apply.
Expected browser result: The browser displays or exposes the structure appropriate for Deprecated Attributes while preserving the semantic relationships expressed by the markup.
Practice exercise
Write a fresh HTML fragment for Deprecated Attributes in Chapter 57. Validate it, remove one important attribute or related element to observe the difference, then restore the correct markup. Test the result with keyboard navigation when interactive, on a narrow screen, and in Arabic or Persian when the content can be translated.
57.3 Avoiding Layout Tables
Avoiding Layout Tables is part of the HTML structure covered in Chapter 57. HTML communicates meaning and document relationships to browsers, search engines, assistive technology, and other tools, so the choice of element or attribute should match the content rather than only its visual appearance.
For Avoiding Layout Tables, examine the element's permitted content, relevant attributes, semantic meaning, accessibility effect, and how it behaves when CSS or JavaScript is unavailable. In obsolete and risky html, the markup should remain understandable as a document before presentation is added.
In Chapter 57, a reliable way to learn Avoiding Layout Tables is to write a small valid fragment, inspect the browser result and document outline, then test one incorrect or missing attribute. This makes the reason for each piece of markup visible instead of treating HTML as a collection of tags to memorize.
Concept in plain language
Avoiding Layout Tables is part of the HTML structure covered in Chapter 57. HTML communicates meaning and document relationships to browsers, search engines, assistive technology, and other tools, so the choice of element or attribute should match the content rather than only its visual appearance.
10 teaching examples
Example 1: Minimal markup
Create the smallest valid support page example that demonstrates Avoiding Layout Tables. Identify which part carries meaning and which parts are only supporting structure. This is Chapter 57, topic 3, example 1.
Example 2: Content variation
Change the text or resource used by Avoiding Layout Tables in the dashboard shell. Confirm that the markup still describes the new content correctly instead of depending on the old wording. This is Chapter 57, topic 3, example 2.
Example 3: Missing-information test
Remove one important attribute or related element from the language page example using Avoiding Layout Tables. Explain what meaning, accessibility, navigation, or browser behavior is lost. This is Chapter 57, topic 3, example 3.
Example 4: Accessibility review
Read the booking page example using the semantics of Avoiding Layout Tables. Check names, labels, landmarks, alternatives, focus behavior, and whether the content still makes sense without styling. This is Chapter 57, topic 3, example 4.
Example 5: Mobile review
Open the media page markup containing Avoiding Layout Tables on a narrow screen. Ensure embedded content, long text, controls, and translated labels do not force the page wider than the viewport. This is Chapter 57, topic 3, example 5.
Example 6: RTL review
Translate the school page into Arabic or Persian. Keep document text RTL where appropriate while URLs, code samples, numbers, and intentionally LTR fragments remain readable. This is Chapter 57, topic 3, example 6.
Example 7: Validation exercise
Run the course lesson fragment using Avoiding Layout Tables through an HTML validator. Fix invalid nesting, duplicate IDs, missing required attributes, or obsolete markup before adding extra features. This is Chapter 57, topic 3, example 7.
Example 8: Progressive-enhancement check
Use Avoiding Layout Tables in the news article so the core content remains useful before CSS and JavaScript load. Add enhancement only after the document structure is complete. This is Chapter 57, topic 3, example 8.
Example 9: SEO and semantics review
Inspect how Avoiding Layout Tables contributes to the meaning of the contact page. Keep headings, links, metadata, and document regions consistent so crawlers and users receive the same primary content. This is Chapter 57, topic 3, example 9.
Example 10: Production review
Review Avoiding Layout Tables in the product description for validity, accessibility, security-related attributes, performance hints, responsive behavior, localization, and maintainability. This is Chapter 57, topic 3, example 10.
HTML code example
<table>
<caption>Chapter progress</caption>
<thead><tr><th scope="col">Chapter</th><th scope="col">Status</th></tr></thead>
<tbody><tr><th scope="row">Forms</th><td>Complete</td></tr></tbody>
</table>Step-by-step code explanation
- Identify the element or attribute responsible for Avoiding Layout Tables.
- Read the markup from the outer document structure inward and verify that each child is allowed in its parent context.
- Check the semantic meaning and any accessibility relationship such as labels, alternatives, headings, captions, or landmarks.
- Open the fragment in a browser and compare the rendered result with the source instead of assuming visual appearance proves validity.
- Validate the markup and test responsive, RTL, and no-JavaScript behavior where they apply.
Expected browser result: The browser displays or exposes the structure appropriate for Avoiding Layout Tables while preserving the semantic relationships expressed by the markup.
Practice exercise
Write a fresh HTML fragment for Avoiding Layout Tables in Chapter 57. Validate it, remove one important attribute or related element to observe the difference, then restore the correct markup. Test the result with keyboard navigation when interactive, on a narrow screen, and in Arabic or Persian when the content can be translated.
57.4 Avoiding marquee-like Content
Avoiding marquee-like Content is part of the HTML structure covered in Chapter 57. HTML communicates meaning and document relationships to browsers, search engines, assistive technology, and other tools, so the choice of element or attribute should match the content rather than only its visual appearance.
For Avoiding marquee-like Content, examine the element's permitted content, relevant attributes, semantic meaning, accessibility effect, and how it behaves when CSS or JavaScript is unavailable. In obsolete and risky html, the markup should remain understandable as a document before presentation is added.
In Chapter 57, a reliable way to learn Avoiding marquee-like Content is to write a small valid fragment, inspect the browser result and document outline, then test one incorrect or missing attribute. This makes the reason for each piece of markup visible instead of treating HTML as a collection of tags to memorize.
Concept in plain language
Avoiding marquee-like Content is part of the HTML structure covered in Chapter 57. HTML communicates meaning and document relationships to browsers, search engines, assistive technology, and other tools, so the choice of element or attribute should match the content rather than only its visual appearance.
10 teaching examples
Example 1: Minimal markup
Create the smallest valid language page example that demonstrates Avoiding marquee-like Content. Identify which part carries meaning and which parts are only supporting structure. This is Chapter 57, topic 4, example 1.
Example 2: Content variation
Change the text or resource used by Avoiding marquee-like Content in the booking page. Confirm that the markup still describes the new content correctly instead of depending on the old wording. This is Chapter 57, topic 4, example 2.
Example 3: Missing-information test
Remove one important attribute or related element from the media page example using Avoiding marquee-like Content. Explain what meaning, accessibility, navigation, or browser behavior is lost. This is Chapter 57, topic 4, example 3.
Example 4: Accessibility review
Read the school page example using the semantics of Avoiding marquee-like Content. Check names, labels, landmarks, alternatives, focus behavior, and whether the content still makes sense without styling. This is Chapter 57, topic 4, example 4.
Example 5: Mobile review
Open the course lesson markup containing Avoiding marquee-like Content on a narrow screen. Ensure embedded content, long text, controls, and translated labels do not force the page wider than the viewport. This is Chapter 57, topic 4, example 5.
Example 6: RTL review
Translate the news article into Arabic or Persian. Keep document text RTL where appropriate while URLs, code samples, numbers, and intentionally LTR fragments remain readable. This is Chapter 57, topic 4, example 6.
Example 7: Validation exercise
Run the contact page fragment using Avoiding marquee-like Content through an HTML validator. Fix invalid nesting, duplicate IDs, missing required attributes, or obsolete markup before adding extra features. This is Chapter 57, topic 4, example 7.
Example 8: Progressive-enhancement check
Use Avoiding marquee-like Content in the product description so the core content remains useful before CSS and JavaScript load. Add enhancement only after the document structure is complete. This is Chapter 57, topic 4, example 8.
Example 9: SEO and semantics review
Inspect how Avoiding marquee-like Content contributes to the meaning of the profile page. Keep headings, links, metadata, and document regions consistent so crawlers and users receive the same primary content. This is Chapter 57, topic 4, example 9.
Example 10: Production review
Review Avoiding marquee-like Content in the documentation page for validity, accessibility, security-related attributes, performance hints, responsive behavior, localization, and maintainability. This is Chapter 57, topic 4, example 10.
HTML code example
<main>
<h1>Modern semantic page</h1>
<p>Use CSS for presentation instead of obsolete presentational HTML.</p>
</main>Step-by-step code explanation
- Identify the element or attribute responsible for Avoiding marquee-like Content.
- Read the markup from the outer document structure inward and verify that each child is allowed in its parent context.
- Check the semantic meaning and any accessibility relationship such as labels, alternatives, headings, captions, or landmarks.
- Open the fragment in a browser and compare the rendered result with the source instead of assuming visual appearance proves validity.
- Validate the markup and test responsive, RTL, and no-JavaScript behavior where they apply.
Expected browser result: The browser displays or exposes the structure appropriate for Avoiding marquee-like Content while preserving the semantic relationships expressed by the markup.
Practice exercise
Write a fresh HTML fragment for Avoiding marquee-like Content in Chapter 57. Validate it, remove one important attribute or related element to observe the difference, then restore the correct markup. Test the result with keyboard navigation when interactive, on a narrow screen, and in Arabic or Persian when the content can be translated.
57.5 Replacing Old Markup with Semantic HTML
Replacing Old Markup with Semantic HTML is part of the HTML structure covered in Chapter 57. HTML communicates meaning and document relationships to browsers, search engines, assistive technology, and other tools, so the choice of element or attribute should match the content rather than only its visual appearance.
For Replacing Old Markup with Semantic HTML, examine the element's permitted content, relevant attributes, semantic meaning, accessibility effect, and how it behaves when CSS or JavaScript is unavailable. In obsolete and risky html, the markup should remain understandable as a document before presentation is added.
In Chapter 57, a reliable way to learn Replacing Old Markup with Semantic HTML is to write a small valid fragment, inspect the browser result and document outline, then test one incorrect or missing attribute. This makes the reason for each piece of markup visible instead of treating HTML as a collection of tags to memorize.
Concept in plain language
Replacing Old Markup with Semantic HTML is part of the HTML structure covered in Chapter 57. HTML communicates meaning and document relationships to browsers, search engines, assistive technology, and other tools, so the choice of element or attribute should match the content rather than only its visual appearance.
10 teaching examples
Example 1: Minimal markup
Create the smallest valid media page example that demonstrates Replacing Old Markup with Semantic HTML. Identify which part carries meaning and which parts are only supporting structure. This is Chapter 57, topic 5, example 1.
Example 2: Content variation
Change the text or resource used by Replacing Old Markup with Semantic HTML in the school page. Confirm that the markup still describes the new content correctly instead of depending on the old wording. This is Chapter 57, topic 5, example 2.
Example 3: Missing-information test
Remove one important attribute or related element from the course lesson example using Replacing Old Markup with Semantic HTML. Explain what meaning, accessibility, navigation, or browser behavior is lost. This is Chapter 57, topic 5, example 3.
Example 4: Accessibility review
Read the news article example using the semantics of Replacing Old Markup with Semantic HTML. Check names, labels, landmarks, alternatives, focus behavior, and whether the content still makes sense without styling. This is Chapter 57, topic 5, example 4.
Example 5: Mobile review
Open the contact page markup containing Replacing Old Markup with Semantic HTML on a narrow screen. Ensure embedded content, long text, controls, and translated labels do not force the page wider than the viewport. This is Chapter 57, topic 5, example 5.
Example 6: RTL review
Translate the product description into Arabic or Persian. Keep document text RTL where appropriate while URLs, code samples, numbers, and intentionally LTR fragments remain readable. This is Chapter 57, topic 5, example 6.
Example 7: Validation exercise
Run the profile page fragment using Replacing Old Markup with Semantic HTML through an HTML validator. Fix invalid nesting, duplicate IDs, missing required attributes, or obsolete markup before adding extra features. This is Chapter 57, topic 5, example 7.
Example 8: Progressive-enhancement check
Use Replacing Old Markup with Semantic HTML in the documentation page so the core content remains useful before CSS and JavaScript load. Add enhancement only after the document structure is complete. This is Chapter 57, topic 5, example 8.
Example 9: SEO and semantics review
Inspect how Replacing Old Markup with Semantic HTML contributes to the meaning of the event page. Keep headings, links, metadata, and document regions consistent so crawlers and users receive the same primary content. This is Chapter 57, topic 5, example 9.
Example 10: Production review
Review Replacing Old Markup with Semantic HTML in the FAQ page for validity, accessibility, security-related attributes, performance hints, responsive behavior, localization, and maintainability. This is Chapter 57, topic 5, example 10.
HTML code example
<p><strong>Important:</strong> Save your work before continuing. <em>Practice regularly</em> and <mark>review errors</mark>. <small>Updated September 2026.</small></p>Step-by-step code explanation
- Identify the element or attribute responsible for Replacing Old Markup with Semantic HTML.
- Read the markup from the outer document structure inward and verify that each child is allowed in its parent context.
- Check the semantic meaning and any accessibility relationship such as labels, alternatives, headings, captions, or landmarks.
- Open the fragment in a browser and compare the rendered result with the source instead of assuming visual appearance proves validity.
- Validate the markup and test responsive, RTL, and no-JavaScript behavior where they apply.
Expected browser result: The browser displays or exposes the structure appropriate for Replacing Old Markup with Semantic HTML while preserving the semantic relationships expressed by the markup.
Practice exercise
Write a fresh HTML fragment for Replacing Old Markup with Semantic HTML in Chapter 57. Validate it, remove one important attribute or related element to observe the difference, then restore the correct markup. Test the result with keyboard navigation when interactive, on a narrow screen, and in Arabic or Persian when the content can be translated.
Chapter 57 review — 10 questions and answers
1. What should you check first when using Obsolete Presentational Elements?
Answer: Check that the markup for Obsolete Presentational Elements matches the meaning of the content, is valid in its context, and does not depend on visual styling to communicate essential information.
2. How do you review Obsolete Presentational Elements before publishing?
Answer: Validate the HTML, inspect accessibility and keyboard behavior where relevant, test narrow screens and translated text, and confirm that Obsolete Presentational Elements adds real document meaning or browser behavior.
3. What should you check first when using Deprecated Attributes?
Answer: Check that the markup for Deprecated Attributes matches the meaning of the content, is valid in its context, and does not depend on visual styling to communicate essential information.
4. How do you review Deprecated Attributes before publishing?
Answer: Validate the HTML, inspect accessibility and keyboard behavior where relevant, test narrow screens and translated text, and confirm that Deprecated Attributes adds real document meaning or browser behavior.
5. What should you check first when using Avoiding Layout Tables?
Answer: Check that the markup for Avoiding Layout Tables matches the meaning of the content, is valid in its context, and does not depend on visual styling to communicate essential information.
6. How do you review Avoiding Layout Tables before publishing?
Answer: Validate the HTML, inspect accessibility and keyboard behavior where relevant, test narrow screens and translated text, and confirm that Avoiding Layout Tables adds real document meaning or browser behavior.
7. What should you check first when using Avoiding marquee-like Content?
Answer: Check that the markup for Avoiding marquee-like Content matches the meaning of the content, is valid in its context, and does not depend on visual styling to communicate essential information.
8. How do you review Avoiding marquee-like Content before publishing?
Answer: Validate the HTML, inspect accessibility and keyboard behavior where relevant, test narrow screens and translated text, and confirm that Avoiding marquee-like Content adds real document meaning or browser behavior.
9. What should you check first when using Replacing Old Markup with Semantic HTML?
Answer: Check that the markup for Replacing Old Markup with Semantic HTML matches the meaning of the content, is valid in its context, and does not depend on visual styling to communicate essential information.
10. How do you review Replacing Old Markup with Semantic HTML before publishing?
Answer: Validate the HTML, inspect accessibility and keyboard behavior where relevant, test narrow screens and translated text, and confirm that Replacing Old Markup with Semantic HTML adds real document meaning or browser behavior.