Selection inside empty element

This is an editable document. When loading this page, the caret should be blinking inside the following brackets. Start typing. The text must be bold.

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An important aspect to consider is that, if you don't type anything when loading the page, but instead use the keyboard to change the caret position, there should be no way to move inside the empty element again with the mouse or the keyboard, which means that it will remain empty forever. This is the desired behavior.

This page is not intended to be compatible with IE, as there are several hacks to make it work there. It should instead work properly with Firefox, Opera and Safari.