Following references with mouse...

[luca . spinacci]

I' d like to use function names in  a buffer as reference
to the real function definition in another buffer using Mouse-2
as reported in emacs manual (http://www.gnu.org/software/emacs)
"26.4 Following References with the Mouse
Some read-only Emacs buffers include references you can
follow, or commands you can activate...
...You can also do this with the mouse, using either Mouse-1 or Mouse-2...
...You can usually tell when Mouse-1 and Mouse-2 have this special sort
of meaning because the sensitive text highlights when you move the
mouse over it..."
How should I set references to my functions and tell emacs to highlight them
so that Mouse-2 take me to the definitions?
Thanks,
Luca.