PS: Is CartoCSS already in use?
CartoCSS is used for the web rendering, while MapCSS is used for JOSM. The
split is unfortunate, but maintaining our own rendering stack that understands
MapCSS will not work because of too few developers. We did this for some
years, but at the end the development of the stack just halted because
everyone has more important things to do.
PPS: How to proceed with ETCS markers as they should(?) be equal in
europe but have different names due to different operating countries?
We use the same markers for multiple countries already:
https://github.com/OpenRailwayMap/OpenRailwayMap-CartoCSS/blob/master/
signals.mss#L660