Not that I would ever consider doing such a think, but for the humble fireman whose duty it is to ring the bell, strict adherence to the bell ringing rules long and loud at every conceivable oportunity is a fine way to annoy an engineer that richly deserves anoying....
Actually at SVRy I think our rules books actually say that the bell shall be wrung at all public crossings untill the entire train has passed through the crossing. Needless to say in the interest of sanity I have yet to see anyone do this after the engine and tender have cleared a crossing. Probably something to look into for the next rule book revision.