Provenance in archaeology means simply knowing where something comes from in a scientifically documented manner. Essentially this means it was dug by a professional who collected all the relevant data as to where it was found and at what depth and in what context, i.e. what was found with it.

The reason this is imporant is it is the only way to date the object and to establish what it means in context. Without provenance the most "earth shattering" discovery is no more than a mere curiosity.

For example if the object is inscribed it could be a forgery unless a professional can produce documentation as to how it was found. And those records must support the dating of the object else it might be a prank forgery buried before the dig began. Alternatively it might be dismissed as a forgery for the "erronius" nature of the inscription but if the find is properly documented then our understanding is erronius and it is not a forgery.

As you can see the concept is important and it cuts both ways. Bibleland has been producing forgeries at least since the fourth century when the wife of Constantine brought back the first in a long line of the true crosses from Jerusalem.

One point has to be emphasized, without provenance it is no more than a curiosity. No matter how important anyone might feel it is, it remains no more than a curiosity. No matter how unfair that might appear it is the fundamental rule. That is why unauthorized digs are criminal. If an amateur were to find the INRI inscription from the cross of Jesus he might as well burn it as simply by removing it he has eliminated all of its archaeological worth.