Question

I use a clear div in several places in a single HTML file, a la:

#clear
{
    clear: both;
}

usage:

<div id="clear">
</div>

But W3C’s HTML5 validator appears to be complaining that each subsequent use after the initial use is a “duplicate ID”:

Why isn’t this valid? How are you supposed to use clear divs multiple times on a single page if it isn’t technically valid?

Note: this is mostly just an informative question, my HTML renders fine on all modern browsers, and given that this is the only error the HTML5 validator can find, I don’t reall care, but I’d just like to know why this is considered to be a problem.

Answer 1

In HTML, id attributes must be unique within the whole document. If you want several clear <div> elements, use a class instead:

.clear
{
    clear: both;
}

---

<div class="clear">
</div>