When creating a new module how do you link it to other modules ?

When creating a new module how do you link it to other modules ?

Hi All,

I created a custom module (what a thrill ! yepiyeh!)
I am very happy about it yet... ;-)

I would like to link it to another module.






















Please look at my image just before and tell me if you can help ??

Thanks so much in advance
Laure