The two flags belong to the nautical code to communicate messages from one boat to another, each flag corresponding to a letter of the alphabet: eg. man at sea or danger.
In our badge (see picture above) the flag on the left corresponds to the letter "A", the initial for Alfa Romeo and superimposed on the flag there is the badge of the Milan car maker.
The flag on the right stands for "P", the initial of Pininfarina, and superimposed there is the badge of the car designer from Turin.
Everything seems correct, but it is not.
In fact, Battista Farina, nicknamed Pinin (which in the Piemontese dialect means "the youngest of the family) turned his surname into Pininfarina, following a Presidential decree, in 1961.
When the 1900 and 2500 were in production, in the Fifties, Battista's last name was still Farina and the firm Pinin Farina.
The flag under the coachbuilder's badge should then be the letter "F" for Farina and it cannot possibly be the "P".