I can't ask simply for all documents "relating to" something. That'll get bounced for not giving a clear enough description for them to be able to find the documents I want with a reasonable amount of effort.

I can ask for a lot of documents (e.g. "all complaints received by TSA", "all management directives", "all emails sent between X and Y", etc) — but they have to be able to find it easily and know what is or is not responsive to my request.

So, please be more specific.