What are reference qualifiers for functions?

According to this webpage, a non-static member function can have a trailing & or && in its declaration. They have the following example

struct S {
    virtual int f(char) const, g(int) &&; // declares two non-static member functions
    };

1) Does the signature of the second function include the virtual?

virtual int g(int) &&

2) What is the meaning of the trailing &&?