Yellow and red striped flag
The yellow and red striped flag warns that the track surface ahead is slippery, usually from oil, water or loose debris.
Also called surface flag
Unlike a yellow flag it does not restrict overtaking — it is information rather than instruction. A driver seeing one knows grip in that section is not what it was on the previous lap.
Marshals will sometimes hold it stationary and rock it from side to side to indicate a small animal on the circuit, a signal more commonly seen at circuits with open surroundings.
Related terms