Drawing of Star Wars: R2D2 and C3P0

Where do the names of the android R2D2 and C-3PO from the 'Star Wars' saga come from?

The name R2-D2, as explained by the own George Lucas (creator of the saga) the name arose while they were working in the post-production of the film 'American Graffiti', specifically in the dubbing. He was looking for some of the scrolls when someone on the team shouted 'R2 D2' (Reel 2, Dialog 2 - roll two, dialogue two). It seems that when he heard it, the light bulb went on and he decided to give that name to one of the robots. It should be noted that despite the premiere of the first film, of the then trilogy, in 1977, I had been working on the project since the beginning of that decade.

To determine where the name of C-3PO comes from is somewhat more confusing and different sources can not agree, there are hundreds of discussion forums on the internet where the subject is talked about without arriving at anything clear. Everything would be easier if Lucas himself said where he came from, as he did with R2-D2.

There are many who say that the name of C-3PO is a nod and reference to the post office of the population where George Lucas nation: C3 was the sector where it is located on the map and PO are the initials of Post Office. But as I indicate, there is no real indication that this is the case or official denials that it is not, so anyway and as it is said in these cases: 'se non è vero, è ben trovato'