Thank you guys! I think I will label 1983 as "linear gas bubble" and put it aside with my (rather few) other
US coins.
I will try to explain with my limited English, what am I seeing on 1972 cent:
It seems to have not centred, like a proper coin. It has a very tiny blank margin on below, and here we call those "off centre" meaning the coin was minted not on the centre of the coin blanc. I assume it's a super super minor thing, yet if that's correct I will label it as off centre and put it next to the 1983 one