In the interest of full disclosure:
Tally = I see the bad / unknown guy. ie "Iceman 2, Tally 2, right 3 low, engaged"
No Joy = I don't see the bad / unknown guy. ie "Iceman 2, No joy, north middle group, blow thru east"
Visual = I see the friendly. Ie "Iceman 2, Visual 2 F-16s right 4...