Kurzov's use of cancelled:()=yes
I use the key-value combination cancelled:()=yes (alternatively, I also use highway=cancelled and cancelled=()) for roads or other features that were planned but never built due to environmental petition, community action, lack of funding, etc, etc...
For example, the Sakatia Ring Road (also referred to as the SRR, pronounced 'serr') in Sakatia, Levarrie was planned to be a full trunk road all the way around the Sakatia metro area, but was either never envisioned or cancelled before the road's building, leaving Sakatians with a non-grade separated but divided highway through the south side of the downtown area, and a grade-separated partial bypass on the rest of the Ring Road.
For the cancelled "Colosseum Extension" of the SRR, I used the tags,
- cancelled:name=Sakatia Ring Road
Please tell me what you think. Or something like that. I dunno.
(edit: thanks markdown, I had to use "()" in place of an asterisk)