As I research the Louvre for an upcoming visit, I find there appears to be two room numbering schemes. In one scheme, the room numbers are all single or double digits; in the other, all rooms are designated with three digit numbers. BOTH schemes are presented on maps from seemingly "official" websites with the URL beginning as louvre.fr....
As an example, one map says Mona Lisa is in room 6, floor 1, Denon wing. The other says room 711, floor one, Denon wing. The two maps show exactly the same museum layout--only the room numbers differ (see links below). Odd, no? Can anyone explain?