The following MO question Why is $O(n;k)$ not connected, and has four connected components? (revisions/timeline)
had the following history
- had a detailed answer
- (a) has been closed as off-topic (by a set $A$ of 5 users)
- had a comment (by myself) suggesting being reopened and then migrated to MathSE
- (b) was reopened (by a set $B$ of five users)
- (c) was closed (by a set $C$ of five users)
- was flagged, then reopened and closed again by a moderator.
The sets $A,B,C$ can be found in the edit history; we have $A\cap (B\cup C)=\emptyset$, while $B\cap C$ has cardinal 3.
That (c) resulted in a closure than a migration is quite puzzling. I thought it means that there were at least 3 closing votes (rather than migration); there was indeed one (as "unclear") when I voted to migrate.
The moderator (Todd Trimble) says that "Ah, here's the deal: it can't be migrated (blocked from asking)." What does it mean technically?