comment-addcomment-add is a variable defined in `
newcomment.el'. Its value is
0Documentation: How many more comment chars should be inserted by `comment-region'. This determines the default value of the numeric argument of `comment-region'. The `plain' comment style doubles this value. This should generally stay 0, except for a few modes like Lisp where it is 1 so that regions are commented with two or three semi-colons.