.... *Article L542-1 of the Code du Patrimoine."
You must be referring to this :
https://www.connexionfrance.com/Pra...-detecting-can-be-a-legal-minefield-in-France
Don't ya just love it ? In the same breath that "dire sounding things" are spelled out, it's the same breath that acknowledges that it's "ambiguous" and that no one gives a rat's #ss in seeking those supposed permissions, or giving-them-out. And gee, I don't hunt for "historical " or "art" items, do you ? I only find modern stuff, eh ?
And do you think anyone is there to rush out, armed with a calculator, to do the math on the ages of coins you or I find ? I mean, .... seriously ??
Also, the dirty little secret is (and same for the other European countries) : Those "dire sounding laws" apply to public land. Yet a farmer can do whatever-the-heck he wants on his private land. Just like ARPA in the USA (which can sound "dire"), yet .... we all know that only applies to federal land (NPS, etc....), and doesn't "subrogate downwards".
Trust me, there's many md'rs in France, and no one cares less.
And as for the "dire sounding" things that someone can find for there, or other European countries : I have a sneaking suspicion of how such things get started. Anyone care to take a guess ? The answer is apparent in the link. You can TELL that some of that wording was crafted as "responses by archies to pressing FAQ's". Eg.: to "not disturb art", blah blah. Yes: The old
"No one cared till you asked" psychology happens on the national scale too.
