The National Security Agency, like most government agencies that deal in many many words and reports, has a style guide. The Strunk and White for spooks was, like most things NSA, a state secret—until it was released under a Freedom of Information Act request by Government Attic, an ad-hoc clearinghouse for fascinating, obscure government documents.

The 266-page manual, first published by the website Boing Boing, begins with “a and an” and ends with ZULU, described as a “phonetic spelling of the letter z.” It’s standard fare for the most part: Grammar tips, ambiguous words, clarifications on usage.

But it’s awash in intelligence and military terms too: We learn that C3 is a symbol for command, control and communications, FROG is an acronym for “Free Rocket Over Ground” (Not to be referred to as a missile) and “conducted operations” and “likely scenario” are listed under “hackneyed phrases.”

LNU should not be used as an abbreviation for “last name unknown,” and Msi is an abbreviation that should be used sparingly “in a short report that mentions only one unit, but freely in listings and narrative reports that repeatedly refer to missile units.” NFI is short for “no further information” or “not further identified,” but should not be used, the manual says. “Unidentified, unlocated and unknown” are better choices.

The list goes on.

The FOIA request was filed by Government Attic in April 2010, and the NSA took almost a year to release it.