HTML

Structure of content on the web

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  • HTML
  • Your first website: Creating the content
  • Headings and paragraphs in HTML
  • Advanced text features
  • HTML images
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  • Content categories
  • Date and time formats used in HTML
  • Viewport meta tag
  • <abbr>
  • <acronym>
  • <aside>
  • <bdi>
  • <big>
  • <button>
  • <center>
  • <colgroup>
  • <del>
  • <dir>
  • <em>
  • <fencedframe>
  • <font>
  • <frame>
  • <frameset>
  • <hgroup>
  • <iframe>
  • <kbd>
  • <link>
  • <marquee>
  • <nav>
  • <nobr>
  • <noembed>
  • <noframes>
  • <optgroup>
  • <param>
  • <plaintext>
  • <rb>
  • <rtc>
  • <script>
  • <slot>
  • <strike>
  • <summary>
  • <td>
  • <th>
  • <tr>
  • <tt>
  • <video>
  • <xmp>
  • Global attributes
    1. anchor
    2. class
    3. draggable
    4. id
    5. itemid
    6. itemtype
    7. popover
    8. tabindex
    9. virtualkeyboardpolicy
    10. capture
    11. elementtiming
    12. min
    13. placeholder
    14. size
    15. <input type="color">
    16. <input type="file">
    17. <input type="number">
    18. <input type="reset">
    19. <input type="text">
    20. global attribute provides microdata in the form of a unique, global identifier of an item.

      An itemid attribute can only be specified for an element that has both itemtype attributes. Also, itemid can only be specified on elements that possess an itemscope attribute whose corresponding itemtype refers to or defines a vocabulary that supports global identifiers.

      The exact meaning of an itemtype's global identifier is provided by the definition of that identifier within the specified vocabulary. The vocabulary defines whether several items with the same global identifier can coexist and, if so, how items with the same identifier are handled.

      Note: The URN may also be used. This inconsistency may reflect the incomplete nature of the Microdata specification.

    • Examples

    Representing structured data for a book

    This example uses microdata attributes to represent the following structured data:

    itemscope itemtype: itemid https://schema.org/Book: urn:isbn:0-374-22848-5
    itemprop title Owls of the Eastern Ice
    itemprop author Jonathan C Slaght
    itemprop datePublished 2020-08-04

    HTML

    html
    <dl
  itemscope
  itemtype="https://schema.org/Book"
  itemid="urn:isbn:0-374-22848-5<">
  <dt>Title</dt>
  <dd itemprop="title">Owls of the Eastern Ice</dd>
  <dt>Author</dt>
  <dd itemprop="author">Jonathan C Slaght</dd>
  <dt>Publication date</dt>
  <dd>
    <time itemprop="datePublished" datetime="2020-08-04">August 4 2020</time>
  </dd>
</dl>

    Result

    Specifications

    Specification
    HTML
    # attr-itemid

    See also