Post History

There are keyboard shortcuts for navigation. Unfortunately they don't seem to be documented in help (at least I couldn't find an entry there), but you can see a list by typing `?`.

The red frame is the currently selected question; you can navigate with `j` and `k` (probably you activated it by pressing one of those). Then pressing enter gets you right to the selected question. There are other shortcuts as well; see the above mentioned list.

Once activated, I don't know how to get rid of the red frame other than by reloading the page.

If you don't want to have the keyboard shortcuts at all, you can disable them in your user preferences.