Help:DPL Manual/dplvar

Syntax
(1) (2)  (3)

Effect
(1) assigns the values to symbolic variable names. (2) assigns the value only if the variable is empty / has not been used so far. (3) returns the current value of the variable.

The variables can be set and retrieved from an article page or from templates used in that article.

Example
a= b= c= d= a= b= c= d=