For a given video on YouTube, you can visit http://youtube.com/watch?v=[code] on any iOS device to see the video.
However, if you use the http://youtube.com/embed/[code] URL — for instance, in an iframe on a page or in a Colorbox modal — it will not play on iOS.
For instance, if you use code like this:
<iframe class="youtube-player" type="text/html" width="640" height="385" src="http://www.youtube.com/embed/VIDEO_ID" frameborder="0">
You just see an error:
Your browser does not currently recognize any of the video formats available. Click here to visit our frequently asked questions about HTML5 video.
To add insult to injury, the link is not clickable on iOS, so I don't know what page that goes to. There is an HTML5 page on YouTube, but it says nothing particularly useful or surprising.
Is there a syntax that can be for iframe embedding that works as expected on iOS?