calculator-user-registerscalculator-user-registers is a variable defined in `
calculator.el'. Its value is
nilDocumentation: An association list of user-defined register bindings. Each element in this list is a list of a character and a number that will be stored in that character's register. For example, use this to define the golden ratio number: (setq calculator-user-registers '((?g . 1.61803398875))) before you load calculator. You can customize this variable.