this is guilt by accusation--a concept of the Roman criminal jurisprudence (as used by Pilate).  The anglo-American system of due process is innocence until proven guilty.  The difference shifts the burden of proof from government to prove the accused is guilty onto the accused to prove themselves innocent. The placement of the burden of proof can determine the winner.

Some additional, hidden questions are:

1. Is there a requirement that questions must not be asked;

2. Is there a time when questions and the asking of them are authorized;

3. When, if ever, are answers to questions required;

4. What relationship must the one asking the question have with/to the one requested/required to answer it, to make silence an answer?

The reasons these questions, and many others like them have not been "pressed" in the courts in the past include, Government had not wiggled its way into a position where it had the authority to examine these questions in detail, Government people were waiting for a time when they were comfortable that they had the authority to demand answers, the people by not understanding everything that is involved in questions being asked may not know how to properly respond without incriminating themselves, even if they respond by taking the 5th.

My question is, what is the standard response that a person should reply with, one that is reasonably non-incriminating in all circumstances, one that is truthful (even though the person responding may think it is not, but uses it anyway), and one that allows the responder time to find competent legal help to decide what the answer should be?

The answer is, "I don't understand." If you look at David DeReimer's information at his old "Peoples' Rights" website, (http://peoples-rights.com/Freedom.htm), you will see that you must present yourself with time to consider your options, along with removing yourself from their immediate authority. "I don't understand" is the basic answer.