Subway station location versus entrance location?

In my area, the subway station locations appear to be, perhaps, the center of the underground station. Unfortunately, the actual entrance could be a block or two away and around a corner. Standing “on the spot”, you might well see the entrance, but then again, you might not. And you might have two choices – one much more convenient than the other – as well.

So my question is: is it a reasonable thing to do to mark actual entrance locations?

(I discovered OpenStreetMap via an iPad-based GPS application, and have set up an account here and started working through the documentation on editing maps. Did a search and didn’t immediately find anything on this topic.)

Place nodes with railway=subway_entrance tag at each of the entrances. These get rendered by osmarender as yellow S symbols: example. But not shown by mapnik at the moment.

The position of subway station railway=station node can be a little bit tricky. Probably best as the centerpoint of the underground structure if you have a way of approximating that, but the railway=subway ways need to pass through this node, so that can make positioning a little awkward