In my area, it’s surprisingly common for clothing stores (especially secondhand stores) to not provide fitting rooms for trying on clothes. Instead, you’re supposed to buy the clothes and return ones that don’t fit well.
When I’ve tagged thrift stores, I’ve wanted to include this information, but couldn’t find a suitable tag. I just found amenity=dressing_room, which I could add as a separate node to indicate the presence of a dressing room. But this doesn’t enable me to note the absence of a dressing room, which I think is more useful/noteworthy information.
Can I use something like dressing_room=yes/no as a tag on the node for the shop? I don’t see any documentation of this existing, and I’m still fairly new to OSM so I don’t quite feel emboldened to make up my own tags.
To your question: If you don’t find a page on the wiki, you can check https://taginfo.openstreetmap.org how often a tag has been used so far. dressing_room=* has been used 14x (12x yes, 2x customers). fitting_room=* has been used 73x already, though. I’m not a native speaker, so there might be other/better words, and in case of doubt the Bri’ish ones win
So in short: you can use dressing_room=yes, but fitting_room=yes has more uses and might thus be the better choice.
As an Australian “English” speaker , I would say that fitting_room would apply to shops such as this, where you try on clothes; while dressing_rooms would be found at theatres etc, where the cast get dressed before going out on stage.
I agree that fitting_room=* is better. I suppose the argument for dressing_room=* would be that there’s also an amenity=dressing_room, whereas there doesn’t seem to be an amenity=fitting_room in the wiki. But a fitting room seems a distinct enough concept to warrant being named differently.
Yes, could easily have both: amenity=fitting_room to map where the fitting rooms are located in a large department store, & also fitting_room=yes/no to show whether or not “small” (but not always - Aldi is one place that sells clothes but doesn’t have fitting rooms!) stores have one.