I recently discovered "c-x n n" to "narrow" (undo with "c-x n w" "widen") a buffer in emacs. This hides everything but the current region from view and modifica

I recently discovered "c-x n n" to "narrow" (undo with "c-x n w" "widen") a buffer in emacs. This hides everything but the current region from view and modification. A tricky command to remember, but as with most obscure commands, if you value it you quickly remember it.