Is this anything l?

My guess it is either a sloppy tooling of the die to remove rust, in which case it will appear on other strikes from same die OR It is a defect in the planchet which should have been eradicated by the heat & pressure from the die impression. So, most likely sloppy “ retooling “ of the die to remove perhaps rust on the die.

Great closeup. But being so microscopic it will not be accepted as a premium die variety.

@numis1652 said:
My guess it is either a sloppy tooling of the die to remove rust, in which case it will appear on other strikes from same die OR It is a defect in the planchet which should have been eradicated by the heat & pressure from the die impression. So, most likely sloppy “ retooling “ of the die to remove perhaps rust on the die.

Those are extremely poor guesses, unless you're intentionally trying to confuse the OP.

The US Mint uses dies VERY quickly. It's basically impossible for a modern die to exhibit rust, or need retooling because of rust.

It looks like a crack and quacks like a crack. Minor die cracks are extremely common. There's no reason to doubt that this is a die crack.