I have two completely different things for you that can both be called “four corners for (or of) registration”.
These doodles are called “registration marks” and are used to line up the different colors. If you are familiar with printing in color (even with little desktop printers), you know that there are usually four colors printed individually: cyan (bluish), magenta (pinkish), yellow and black. Each color is printed separately from the rest of them and, when the four layers of single color are on the same paper, they form a color image.
Ofcourse, if they are not aligned correctly, it looks ugly. These marks somehow help the print operators and also the printers and presses themselves to line them up correctly.
I don’t care though, because this looks like a particularly interesting map of a four corners. What’s that on the corner? A water tower? And the green line could be a trolley track from west to north. Some cars are present on the south and east.
The liquid cockroach was a spot of glue that took off some of the cardboard it was pressed against.
To register to vote in Oklahoma, you may (if you don’t have an address) have to draw a map. I never thought cartography would be a prerequisite to enfranchisement. I wonder if anyone has ever tried to claim this was an illegal literacy test?
The image above in context can be seen at the entire form, here.