Watch Your Six
During the show, as in many others, “watch your 6” or “I’ve got your 6”, is a common phrase. The meaning of this “6” is the area directly behind someone. It comes from WWII pilots who would refer to each direction like the hours of a watch. 12 o’clock means straight ahead, for example.
Chicago Hope
Before they ever made their way to the set of NCIS, Rocky Carroll (Vance), Lauren Holly (Director Shepard) and Mark Harmon (Gibbs) all acted together on the set of Chicago Hope. Their stint there lasted from 1996 until 2000.