Hallo Sarah,
That was new to me, I should reread the Wiki more often.
That's why I'm working on http://access.t-i.ch/ ;-)
Is there something like http://wiki.openstreetmap.org/wiki/DE:Road_Signs for signs that are different in Switzerland? For example, I'm still unsure how to tag the difference between http://www.ellgass.ch/catalogue/art_2.13.htm and http://www.ellgass.ch/catalogue/art_2.14.htm .
That's a Swiss question indeed, as most other countries only know sign 2.13 (car and motorcycle). I would tag 2.13 as motorcar=no and motorcycle=no and 2.14 as motor_vehicle=no.
Maybe a better way would be to tag 2.13 as motor_vehicle=no, moped/mofa=yes, as it is not yet clear if moped/mofa is a child of motorcycle or not.
I once tried to clean up the wiki-page about access, but maybe it's better to visualize it with a hierarchical diagramm.. http://wiki.openstreetmap.org/wiki/Key:access http://wiki.openstreetmap.org/wiki/DE:Key:access
Regards, Thomas