Is it "User Reject Soft Fork"?
It sounds another softfork from old chain and hardfork from miner driven softforked chain.
Am I understanding correctly?
Discussion
It is basically saying that any blocks signaling for drivechains activation will be rejected by nodes as invalid. If there is a significant adoption of URSF by ecnomically important nodes, the miners won't even bother.
It is hardfork, right?
No it is a constriction of the existing rules for acceptable blocks.
Then the other softfork(maybe miner driven softfork) becomes hardfork. It seems that the term is not that critical.
Thank you.
Two soft forks in disagreement does not equal one hard fork. The rejecting node rejects, and the activating node signals/accepts. All actors take risk in being on the wrong side of a reorg, but the miners have to choose especially carefully, because they have risked their income.