In WWII the German Navy used (bow to stern) Anton, Bruno, Caesar, Dora.
The British used (bow to Stern) A, B, X, Y. The Dido-class (unusually for the British) had three turrets forward and used Q for the 3rd.
I am not sure what the British called the 3rd turret on Nelson and Rodney though.....
According to this http://theminiaturespage.com/boards/msg.mv?id=440858, probably C
For the secondary, it was P# and S#. For example, the four 5.25" batteries on either side of the KGV class were S1 to S4 and P1 to P4.
American ships were by type and location. eg Iowa class main battery would be 161, 162, 163. Don't know about the secondary batteries.
< Message edited by Aurelian -- 10/27/2017 3:31:47 PM >