Suzanne Dryden Kuser knew some secrets, and she took them to her grave. It says right on her gravestone "I still cannot tell you." But that's engraved under a string of intriguing numbers and letters.
Kuser came from a prominent family of politicians; both her father and her brother have Wikipedia entries, as well as many of her other ancestors. "Sukie" herself had quite a career, beginning at the National Security Agency as a cryptologic linguist, then working at the State Department for 58 years. Kuser ended up as the head of the U.S. State Department's Intelligence Reporting Division before retiring. But even then, she was a consultant and reviewed classified documents.
However, the code on her tombstone, while a memorial to her work, was designed to be decodable by anyone interested. Several commenters at reddit figured it out easily. Each word begins with a letter that is linked to the alphabet backwards, meaning a Z would be an A, a Y would be a B, etc. The rest of the letters are numbers, also keyed to the alphabet but in a somewhat more difficult manner. You don't even need the number key because the numbers that are doubled correspond with the doubled letters in the answer, but ThymeIsTight posted a key to make it all clear.
But you don't want to go to all that trouble, so I will tell you what the code actually says. Show Answer
A fitting memorial for a talented public servant.
(Image source: Photo_Shop_Beast)