I have alot of 1990 no mint marks,this one has a raised crack on the "reverse" side. The crack even goes over onto the memorial part of the steps. Is this one a good one?. I will post later a 1960 no mint mark believed to be a proof.
Die cracks are very common on all denominations and can be found almost anywhere on a coin. That is why they are not worth much. By the way, all "no mintmark" Lincoln cents are produced by the Philadelphia Mint. 2017 is the only year in which the Philly mintmark (P) was included on the Lincoln cent, but it was discontinued in 2018. Chris