Tardis:Romana

We've decoded to refer to the Romana played by Mary Tamm as "Romana I"; the one played by Lalla Ward as "Romana II", and the incarnation depicted in The Shadows of Avalon and other BBC Eighth Doctor Adventures as "Romana III".

We fully recognise that she's never known within a narrative by these names — although the Big Finish Gallifrey series does definitively call Ward's Romana the "second" one and Tamm's the "first".