[pointerevents] The specification of `relatedTarget` property of `mouseover` reads "indicates the event target a pointing device is entering, if any." but should read "exiting" (#630)

sbates-idrc has just created a new issue for https://github.com/w3c/pointerevents:

== The specification of `relatedTarget` property of `mouseover` reads "indicates the event target a pointing device is entering, if any." but should read "exiting" ==
I believe that I have found a bug in the specification of the `relatedTarget` property of the `mouseover` event. The specification differs from what I am seeing in Firefox, Chrome, and Edge. And differs from the Mozilla documentation and the specification of the related `mouseenter` event.

The specification of the `relatedTarget` property of the `mouseover` event (https://w3c.github.io/uievents/#event-type-mouseover) reads:

"indicates the event target a pointing device is entering, if any."

But I think that it should read:

"indicates the event target a pointing device is exiting, if any."

When testing `mouseover` events in Firefox, Chrome, and Edge I see that the `relatedTarget` property is set to the element that the pointer exited. I have created a test file here: https://gist.github.com/sbates-idrc/b47ebb07ab95a4e50dd64b7933351de1

Moving the pointer from `div` A to `div` B results in the following being logged:

* `target: div B`
* `relatedTarget: div A`

This behaviour is consistent with the Mozilla documentation: https://developer.mozilla.org/en-US/docs/Web/API/MouseEvent/relatedTarget

The specifiicaion of the `relatedTarget` property of the `mouseenter` event reads: "indicates the event target a pointing device is exiting, if any." (https://w3c.github.io/uievents/#event-type-mouseenter)


Please view or discuss this issue at https://github.com/w3c/pointerevents/issues/630 using your GitHub account


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Received on Monday, 12 January 2026 22:10:40 UTC