How to display customized message in jQuery validate for groups

Question

I am trying to follow DRY for codes.

The rules is validating url with jQuery validate plugin, desired result is customized message.

This JScript validate the rule, but display default message from browser. How can I link the message to groups=grp for rules.

$(function(){

    $("form[name=principal]").validate({
        groups: { 
            grp: "faceb tweeter googlep linkedin instagram youtube"
        },
        rules:{
            email:{
                required: true,
                email: true
            },
            n_radios:{
                required: true
            },
            gpr: {
                url: true
            }
        },
        messages:{
            email:{
                required: "La direccion email es requerida",
                email: "ingrese un <b>email</b> valido"
            },
            n_radios:{
                required: "Selecciona una lista"
            },
            grp: {
                url: "El formato del link debe ser h_ttp://site.com o h_ttps://site.com"
            },
        };
       
    });
});