Unanswerable

I had a high school youngster who learned that I was interested in the railroads, and he asked to see some pictures of DRGW locomotives. He started asking me some questions that I thought that I could answer, but discovered that I could not. He asked about the colored lights on the front of the locomotive, and I said that they were classification lights (regularly scheduled train, extra . . .). The question was, who needed to know (the crew should have known what they were, why would the public need to know - and would they know the difference). The he asked about the lights. Two stacked above the cab, and then 2 more on the nose on a low hood. Question was - who said they needed four headlights (good question - specific railroad request or required by Feds, and if so then, why NOT now). Plus ditch lights he asked, isn't that overkill, and how much more did the extra lights help (probably more for the motorists to see the damn train coming). But the kicker question was - why the "F" on the locomotive, which of course indicates the front, so his question was of course, the crew needed to know this? Anyone got some answers so I can get back with the kid and not appear a complete idiot.