# Semantic Elements

* :green\_book: [Semantic Elements in HTML](https://www.w3schools.com/html/html5_semantic_elements.asp) (W3Schools)
* :green\_book: [Introduction to ARIA](https://developers.google.com/web/fundamentals/accessibility/semantics-aria) (Google)

{% hint style="info" %}
[ARIA](https://developers.google.com/web/fundamentals/accessibility/semantics-aria#what_can_aria_do) can **modify** existing element **semantics** or **add semantics** to elements where no native semantics exist.
{% endhint %}

## semantic element list 

|  #  | tag                                                                          | inline               | meaning                                                                                 |
| :-: | ---------------------------------------------------------------------------- | -------------------- | --------------------------------------------------------------------------------------- |
|  1  | <**main**>                                                                   | :x:                  | there should be **at most one main** on each page.                                      |
|  2  | <**section**>                                                                | :x:                  | **generic section** of a document.                                                      |
|  3  | <**nav**>                                                                    | :x:                  | **navigation** part of a document.                                                      |
|  4  | <**article**>                                                                | :x:                  | **independent**, **self-contained** content.                                            |
|  5  | <**aside**>                                                                  | :x:                  | sidebar.                                                                                |
|  6  | <**header**>                                                                 | :x:                  |                                                                                         |
|  7  | <**footer**>                                                                 | :x:                  |                                                                                         |
|  8  | <[**mark**](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/mark)> | :question:           | marked/highlighted text.                                                                |
|  9  | <**time**>                                                                   | :white\_check\_mark: | date/time.                                                                              |
|  10 | <**figure**>                                                                 | :x:                  | annotate illustrations, diagrams, photos, code listings, etc.                           |
|  11 | <**figcaption**>                                                             | :x:                  | provide a caption for the parent <**figure**>  element.                                 |
|  12 | <**details**>                                                                | :x:                  | parent container of <**summary**>, constains additional info.                           |
|  13 | <**summary**>                                                                | :x:                  | A piece of text that **when clicked**, opens/hides a panel with additional information. |

### about \<details> disclosure marker

{% hint style="warning" %}
Different browsers have their own implementations of how we can deal with the **marker** for the <**details**> elements. As W3C **hasn't defined** a **selector** for that **marker**, to disable it, you need to use a **proprietary pseudo class** :

**`summary::-webkit-details-marker { display: none; }`**

You can use that same selector to style the marker differently. Currently, there is **no way** of **animating** the open and close.
{% endhint %}

## **ARIA Landmark role**

* :green\_book: [Use Sectioning Elements to Create Landmarks](https://www.hassellinclusion.com/blog/html5-sectioning-elements-accessible-landmarks/)

| role          | corresponding element                                                                     |
| ------------- | ----------------------------------------------------------------------------------------- |
| banner        | \<header> :asterisk\_symbol:                                                              |
| navigation    | \<nav>                                                                                    |
| main          | \<main>                                                                                   |
| complementary | \<aside>                                                                                  |
| form          | \<form>                                                                                   |
| contentinfo   | \<footer> :asterisk\_symbol:                                                              |
| region        | \<section>                                                                                |
| search        | <p>no corresponding HTML5 element.<br>use <strong><code>role="search"</code></strong></p> |

:asterisk\_symbol: not contained within other elements


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://lochiwei.gitbook.io/web/html/semantic.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.