The main issue comes from code like this (https://godbolt.org/z/GY5baP18q https://godbolt.org/z/GY5baP18q): #include <stdio.h> typedef int int_func(int

The main issue comes from code like this (https://godbolt.org/z/GY5baP18q https://godbolt.org/z/GY5baP18q): #include <stdio.h> typedef int int_func(int x); void print_result(int_func *func, int x) { printf("%d\n", func(x)); } int f(int x) { return x; } _Alias f_alias = f; static int_func * const f_ptr = f; void doesnt_work(int x) { print_result(&f, x); print_result(&f_alias, x); //print_result(&f_ptr, x); //error: incompatible pointer types } Since &f is of type int_func *, an alias to f must behave such that taking its address still results in an int_func *. Otherwise, existing code is broken, as shown above, since f cannot be replaced with f_ptr in the expression. This is what _Alias is meant to solve: it's perfectly transparent, in that the end-user has no way to distinguish whether the name comes from the original declaration or an _Alias. This allows libraries to modify the external name of a function, without breaking code that depends on the syntactic name of the function.