"Identify Results" in Post Processing does not show the option "By Node IDs" in the drop down menu for selecting the (nodal) result. Instead it shows the option "By Element IDs".
The drop down menu for selecting the result inside the "Identify Results" window is adjusting to the results that are currently being displayed.
E.g. if we see the option "By Element IDs" instead of "By Node IDs" for Element-Nodal stress results, this is because the nodal results are not being averaged on the nodal (ID) location. Hence, one node ID can have multiple results depending on the connected elements.