A Blackflag on Yoshi's Cookie.
The unfortunate anomaly of a blackflag (often shortened BF) is when you get a result of 1 good clean on a song. (1-0-0-0) Nobody knows why it's so hard to avoid these, but people have joked that in order to get a AAA, you have to get a blackflag first.
There are also variations on the blackflag for scores where you might get :
- 0-1-0-0 or avflag
- 0-0-1-0 or missflag
- 0-0-0-1 or booflag
- 1-1-1-1 or rainbowflag/omniflag