If Rand's quarters were on deck 12, why does her door say 3C 46? Hmmm?
Maybe it means Section 3, Deck C, Room 46. The number C in the hexadecimal numbering system is equivalent to 12 in the decimal system. I recall years ago in either my French class or Computer class the instructor stating that the French use 3 numbering systems: Octal (base 8), Decimal (base 10), and Hexadecimal (base 16). Maybe Starfleet uses hexadecimal instead of decimal.
So Section 3, Deck C, Room 46 in hexadecimal is equal to Section 3, Deck 12, Room 70 in decimal.
Just a thought,
Navigator NCC-2120 USS Entente
Stokely: In an insane society, the sane man must appear insane.
Harvey Holroyd: Where'd you get that?
Stokely: Star Trek. [leaves the room]
Harvey Holroyd: [to himself] God, I miss that show. (Source: "Serial", 1980.