Here is a perfect example of the information that a letter CAN tell you. Most just let you know as others have said, basic configuration and when it was shipped and to who.
But once in awhile SURPRISE!!
( From Wiki )
Wesley Grapp served as head of the Los Angeles Federal Bureau of Investigation (FBI) office. He was the agent who carried out Hoover's orders to give FBI information to University of California senior regent Edwin W. Pauley. Pauley allegedly had a history of political connections with the Office of Strategic Services (OSS), forerunner of today's CIA, as well as a close association with Will Jenkinson, who was later to serve as director of the Central Intelligence Agency, (1953–1961).
Grapp left the FBI in 1972 and headed security for Flying Tigers Airlines.
Edwin W. Pauley
Pauley told Grapp that in the 1950s the FBI secretly gave the university reports on professors it was considering hiring. He said he wanted to restore the procedure—which the FBI had code-named the Responsibilities Program—and offered to pay someone to check FBI files. After Pauley promised not to reveal that the FBI was his source, Grapp gave him a report on UC Berkeley immunology professor Leon Wofsy that summarized news stories from 1945 to 1956, noting that Wofsy had been a self-avowed Communist Party official who tried to get young people involved with the party. The report failed to note that since 1957 the FBI had found no evidence that Wofsy had been involved with the party.[14]
On February 4, 1965, Grapp told Hoover that Pauley could be used as a source on internal University affairs, and could harass and remove suspected communists on the faculty and the Board of Regents. Hoover approved, and one week later Pauley was given confidential information on Coblentz, Roth and Heller. Pauley, Grapp reported to Hoover, was "most appreciative" of the information on his opponents. As Pauley saw it, according to Grapp's report, UC would remain in turmoil "as long as the current officials were in power at the university."[14]
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