Data (<data>)

When To Use

• To make the content visible to the user and also provide a version of the data that can be interpreted by scripts. ¹

Rules

• This example demonstrates the usage of the element where the content enclosed within the element is visible to the user, while scripts can retrieve this content using the "value" attribute. ¹
• This element does not offer any additional advantages in terms of accessibility. 

Examples

Associate a product number with a T-Shirt in a list:

<ul>
    <li><data value="1">Small T-Shirt</data></li>
    <li><data value="2">Medium T-Shirt</data></li>
    <li><data value="3">Big T-Shirt</data></li>
</ul>

Sources 

1. MDN: <data>: The Data element by Mozilla contributors is licensed under CC-BY-SA 2.5
2. Quackit: HTML 5 <data> Tag © Copyright Quackit.com