What about highway?
I would like to start a discussion about what extra tags are/should-be/will-be useful in addition to just piste:type=*. Currently, in the absence of any highway=* tag, then ski trails such as piste:type=nordic are absoluteley not shown in OpenStreetMap. I know that the rule is "don't tag for the renderer", but still, this is OpenStreetMap.org's own renderer which never shows ski trails (save if also a highway)...
In general I add highway=construction, construction=service/path & winter_road=yes : this causes the trail to be marked as a dashed line (by OpenStreetMap.org itself, for example, mainly due to highway=construction). When editing the map details, then the winter_road=yes makes it (slightly more) obvious that there is no all-year road in that location.
Can we please have some discussion on this issue so that a consensus may be reached, and then respected by all. Perhaps then others will stop removing these tags, as soon as I have finished adding them... --Neil Dewhurst, Lyon France (talk) 09:27, 23 March 2015 (UTC)
I just discovered "missing" trails in Peter Lougheed Provincial park, Alberta, Canada. I was about to add them from my GPS track data. They were already there but missing a highway= tag. The trails that do show up on the map are tagged highway=path (the trails are walking or cycling trails in the summer. David Dermott (talk) 20:37, 1 January 2016 (UTC)
Ya don't map for the renderer, as tempting as it may be. It makes the data inaccurate which can create worse problems such as headaches for people using other apps using OSM data which use a different rendering schemes. Try OpenSnowMap.org. It would be nice for OSM render ski trails. I know Google maps does and looks good. DFyson (talk) 05:55, 21 March 2017 (UTC)