Tagging multiple subway entrances (protocol)?

Underground subway stations are marked in my area with a single point. Apparently, this is the center of the station or some other official location, but it does not correspond to the station entrance(s), which may be a hundred meters from this point, and around a corner – hence not visible from the marked POI.

Is there any protocol or advice for marking the actual station entrances? I don’t want to clutter the map with two or three more points if the “mark the center of the station and let people figure out how to get on” marking is the openstreetmap way of doing things.

If marking multiple entrances is acceptable, I believe that inside the stations, they usually refer to the exits by street they are located on – if there actually are multiple entrances. To what degree should I care about text length, however? That is, “Courthouse N” and “Courthouse S” are nicely compact, even if they are not the way the subway employees would refer to them.

Thanks!

http://wiki.openstreetmap.org/wiki/Tag:railway%3Dsubway_entrance

Thanks NE2, that’s exactly what I’ll do.