It's called, "Growing Baccatum in Hot Humid Climate" disease.
.
If there's anyone growing any Baccatums near an Atlantic of Gulf Coast, in zone 8 or higher, that doesn't have some of these spots, please raise your hand...
.
The real question is, do you have tons of this type of foliage, or did you just obsessive compulsively select 2 leaves off of an entire plant? (that's my funny way of saying, why don't you show us the plant, instead of select foliage)