J. Edgar Hoover was the director of the U.S. Federal Bureau of Investigation from 1924 until his death in 1972. He was one of the most powerful men in the world,and if his word wasn't law, there was no practical difference to those who worked for him.

Once during the 1960's, an aide submitted a memo to Hoover, only to find it returned with a single cryptic comment written on the first page: "Watch the borders."

Well, when Hoover told them to jump,they jumped and stayed in the air until he told them to come down. FBI agents were dispatched to Texas, California, Minnesota,and Washington. Their instructions included: "Watch the borders".											Once in place, the agents' pulses slowed down and their brains sped up. What, exactly, were they to be watching ''for''? Eventually, this question made its way back up the chain of command, and at last Hoover's aides braved his displeasure by asking him for further instructions. Hoover explained that the margins on the memo were too narrow, and that typists should watch the borders.

When Hoover died, even hard-cases wanted nothing to do with Hoover's personal files. They were burnt unread.
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Watch the borders is the phrase I think of when an indirect directive is given and its meaning is unclear.
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See: CommunicationsDependOnClarityOfPresentation