IIRC, the mintmark must be below of the date and cannot intersect it or touch the portrait, and that's about it.
Those two particular cents are actually pretty similar. I've seen (photos of) 1950s cents whose mintmarks really were all over the place (up to and including almost touching the date).
Those two particular cents are actually pretty similar. I've seen (photos of) 1950s cents whose mintmarks really were all over the place (up to and including almost touching the date).





















