This is great. A family kept a mysterious note from their grandmother for 20 years. The note was a series of letters, clearly some sort of code. Try as they might, they could not decipher this last message from grandma. So they posted it online. 15 minutes later, they had their answer.

I don’t want to spoil the surprise, so I won’t post the resolution here. Read the thread from top to bottom. See if you can work out the puzzle before you get to the end of the thread.