Does about:blank work in all browsers?

Question

I have an iframe and I want to clear it, so I set its src to about:blank

Then I wondered, does this work in all browsers?

Answer 1

It is safe to use in all browsers I know of, but, from the Wikipedia article:

It is not an officially registered scheme, and has no standard syntax.

There is no guarantee this will be accepted as a valid URL by all clients.

I would be interested to hear about an "empty URL" approach that is guaranteed (by the spec) to work everywhere.