Why few fielders wearing two caps at the time of fielding?

Q&AWhy few fielders wearing two caps at the time of fielding?
Saby asked 1 year ago

During the ipl match between hyderabad and chennai I seen Kane Williamson wearing two caps. During recent australia vs england series Aron Finch wearing two caps in every single game. Is it new rule that few fielders wear two caps during fielding.