The FOIA and those who implement the Act, know that the use of terms and phraseological terminology is very important. Any one who is new to the FOIA in the US, will quickly learn that phasing their requests precisely is vital, since the interpretation of the wording can effect the search for any potential records or data.
Also doing some preliminary research and have some knowledge of the FOIA for that particular agency is important. This will provide you with some information has to where the information you seek maybe located, and also knowledge of the restrictions and denials, under the FOIA of potential data, and it will give you some grounds for appeals if that is the case.
Having knowledge of some of the terms used for a certain subject, especially if it is used by the agency or military command, is very useful. You could request documents on a certain subject, which has a known term in the public, and get a no records response. Yet the agency, or command, could have records but not under the term or terms you have requested information for.
You must be VERY precise if you can, generalizations, usually can bring a negative or confusing response.