[Tagging] railway=subway_entrance vs railway=train_station_entrance

[Warin]

On 20/6/25 23:32, Michael Tsang wrote:
> Hi all,
>
> railway=subway_entrance is widely used for station entrances, where the wiki
> says that "A subway entrance is a place where people enter or exit a subway
> (metro) station." However, there is also a similar tag called
> railway=train_station_entrance, which is not as widely used (and not rendered
> on OSM Carto), which the wiki says "A train station entrance is a place where
> people enter or exit a train station." The remaining contents are nearly the
> same in both articles, and I believe they are the same concept.
>
> Can any clarify if there are any actual differences in the usage of these two
> tags?

Subway, Metro stations I would take as being underground stations.
The other tag is not specific as to being above ground or under ground.

In Australia underground stations carry 'mainline' trains. They don't 
usually carry freight or long distance trains as these are diesel powered.