Romii
From Memory Alpha, the free Star Trek reference
Since the name "Romii" merely appeared on a map depicting the Neutral Zone, it has not yet been clarified whether Romii is the designation for a star, star system or a planet. There have been suggestions that Romii and Remus are the same world, though this would contradict the visual evidence shown in the map.
A possible in universe explanation is that "Romii" was simply an older way of writing "Remus." A real world example of this is how Tokyo used to be written "Tokio."
