8.1.2. Tag ordered lists with <ol> and <li>

Use the <ol> and <li> tags to tag lists of items that must be shown in a specific order (list of steps in a procedure, ranking, etc.)—in other words when the information would not be understood if the items were entered in a different order.

If required, make sure that lists are properly nested:

<ol>
    <li>First item of first level</li>
    <li>
        Second item of first level
        <ol>
            <li>First item of second level </li>
            <li>Second item of second level </li>
        </ol>
    </li>
    <li>Third item of first level </li>
</ol>