Function: set-default
set-default is a function defined in data.c.
Signature
(set-default SYMBOL VALUE)
Documentation
Set SYMBOL's default value to VALUE. SYMBOL and VALUE are evaluated.
The default value is seen in buffers that do not have their own values for this variable.
Probably introduced at or before Emacs version 18.
Source Code
// Defined in /usr/src/emacs/src/data.c
{
set_default_internal (symbol, value, SET_INTERNAL_SET);
return value;
}