The discoloration is a water stain.
Side note: See the two holes at the top left? This was from the days before the invention of the paper clip, when documents were held together with straight pins.
Bonus side note: We’re still working on the campus art inventory!
At least the letter wasn’t damaged by fire.
But I’ll bet you have a lot more to inventory (is that a verb?) these days!
Amusing and timely!
At least it was not a flood….
I’ll bet that water stain was from when Brown and Root burst some pipes in the AC system back in 1992 ! 🙂