One particular term that is used to name copper blocks is "semi-weathered", and the spelling of this term is inconsistent, where sometimes it is spelled with a hyphen and other times without. Attached is one picture of a copper block that includes "semi-weathered" with a hyphen and another picture of a cut copper slab that includes "semi weathered" without a hyphen.
It seems that only the slabs are affected, the normal blocks and the stairs are spelled correctly, but both slabs (normal and waxed) are spelled inconsistently.