Semantic structure · Lesson 9 of 10 · 7 minutes

Semantic structure: Nested heading order

Heading order follows the relationship between topics. A subsection of h2 normally starts at h3.

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Your objectives

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1
Build nested heading order
Build this first target: <h1> containing “Server handbook”. Inspect the structure before checking the lesson.
Hint & worked example
Heading order follows the relationship between topics. A subsection of h2 normally starts at h3.
The requested elements, attributes, content, and hierarchy exist outside comments.
```
<h1>Server handbook</h1>
```
Common mistake to avoid: A visual appearance alone guarantees the intended HTML meaning.
2
Extend the nested heading order example
Extend your file to include: <h1> containing “Server handbook”; <section>; <h2> inside <section> containing “Logging”. Inspect the structure before checking the lesson.
Hint & worked example
Heading order follows the relationship between topics. A subsection of h2 normally starts at h3.
The requested elements, attributes, content, and hierarchy exist outside comments.
```
<h1>Server handbook</h1>
<section><h2>Logging</h2></section>
```
Common mistake to avoid: Replacing semantic elements with generic divs automatically improves accessibility.
3
Verify the complete nested heading order pattern
Finish the pattern with: <h1> containing “Server handbook”; <section>; <h2> inside <section> containing “Logging”; <section> inside <section>; <h3> inside <section> containing “Retention”; <p> inside <section> containing “Keep the required evidence window.”. Inspect the structure before checking the lesson.
Hint & worked example
Heading order follows the relationship between topics. A subsection of h2 normally starts at h3.
The requested elements, attributes, content, and hierarchy exist outside comments.
```
<h1>Server handbook</h1>
<section><h2>Logging</h2><section><h3>Retention</h3><p>Keep the required evidence window.</p></section></section>
```
Common mistake to avoid: A visual appearance alone guarantees the intended HTML meaning.

Understand the pattern

Heading order follows the relationship between topics. A subsection of h2 normally starts at h3.

Misconceptions to reject

A visual appearance alone guarantees the intended HTML meaning.
Replacing semantic elements with generic divs automatically improves accessibility.

The preview is a sanitized subset, not a full browser compatibility test.

Worked example and expected result

<h1>Server handbook</h1>
<section><h2>Logging</h2><section><h3>Retention</h3><p>Keep the required evidence window.</p></section></section>

Heading order follows the relationship between topics. A subsection of h2 normally starts at h3.

Try a variation

Adapt the final example to a different project name while retaining its structure and relationships. A different context still needs a real browser and accessibility check.

Explain it

Which statement correctly explains nested heading order?A visual appearance alone guarantees the intended HTML meaning.Replacing semantic elements with generic divs automatically improves accessibility.Heading order follows the relationship between topics. A subsection of h2 normally starts at h3.

Apply it elsewhere

You reuse nested heading order in a different project. What must still be verified?Only whether the source code has the same number of lines.The meaning, relationships, and accessible names in the new document.Nothing; passing a single exercise guarantees every future use.

Keep the momentum.

Complete the lab, then explain and apply the pattern.

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MDN: HTML structure