Washington (CNN) -- The pages read like a modern-day Harry
Potter novel. But the writing does not denote the characters Ron
Weasley saying, "There's nothing written in this diary," and
Hermione Granger responding, "It must be invisible ink!" These
are newly-declassified, nearly century-old CIA documents, typed
and hand-written with titles like "Secret Writing" that, among
other things, divulge formulas for making and uncovering
invisible ink. The six papers date as far back as 1917, and
until their release on Tuesday were among the United States'
oldest classified documents. One of them lists ingredients used
in German secret ink. Whereas the Harry Potter character
Hermione can simply command "Aparecium!" to make the words
appear on the page, these documents indicate early 20th century
spies had to employ much more elaborate methods. The CIA
released the documents to the public because the information
contained in them is no longer considered to be sensitive. They
are believed to be the only remaining classif