Usage question: module_function

[EDIT: Since I didn’t get a response here, I cross posted the question
and received an answer, so I consider it solved]

Consider this module:

module MM
def f
def self.g
module_function :f

Both, f and g, are module functions, and can be called as


Is it just a matter of taste, or might there be good reasons to choose
one way of defining a module function over the other?

I am aware, that there is a difference, when I am using the module as
a mixin:

class CC
include MM

In this case, f is available also as an instance method within CC, while
g is not. However, this doesn’t look to me as a particularily
interesting feature: If I design a module to be used as a mixin to a
class, I don’t see why I would use module_function. Are there other
reasons why I would favorize either self.FUNCTION or module_function
when defining a module function?