It is up to the justice or judge to decide whether your menu, as you might call it, or your items to be searched for are pertinent to your investigation.
Part of the issue you experience as a police officer is not being able to establish exactly what types of records are kept and exactly what they're called. You could miss records depending on what's kept by the entity itself. You don't always have that back-and-forth, that ability to contact the entity itself and ask those questions as to what types of records they keep, how long they keep those records for and so on. If you don't have knowledge of exactly what's kept, and you send a production order asking for general information, then you might miss out on key evidence that would lead you potentially to other types of....