Go to OpenstreetMap.org.
On the right hand side of the screen, select the layers option and then the "Transport Map"
Find the station that you want the info for and with the "Query features" enabled on the right menu, click on it
On the left hand side you should get the query results that show the station and other associated Transport info
The CRS code is listed as ref:crs
So in this case the code to use would be EPS