Why Endhiran 2 became 2.0 and  Singam 3 became S3?

First, it was revealed by director Shankar that 2.0 will be the title of his next film with Rajinikanth, which is eventually the sequel to Endhiran. Recently, first look posters of Suriya's S3 (third film in Singam series) were released. One would wonder why the films aren't titled Endhiran 2 and Singam 3 respectively. 

As the film title's rights belongs to a producer, it is usually not easy for a team to use the title if they are making a sequel with a different producer. Endhiran's title was registered by Sun Pictures, while 2.0 is being produced by Lyca Productions. Similarly, Sun Pictures might have a share on the title rights of Singam. Hence, the production companies might have played safe by going with shortened forms of the titles..

On the contrary, producers can capitalize on the title's brand image even if the team is entirely different. That's how Villa was marketed as Pizza 2 and KO2 is currently underway.

Also Read: Singam 2 Title and Logo Confirmed