EC-145 "Shadow" ?

[Daveroo]

Last night around 8-ish? pst,i was hearing a male voice on 122.700 unicom for KAUN (auburn),he was announcing "shadow EC-145 inbound runway 25" blah blah....the rest doesnt mater...but he said "shadow" atleast a dozen times,i know the Lakota is the military version,,,so why would he say shodow over and over?...maybe he was police?....the placer county SO has a

AS350B3,and they go by "Falcon 1" ,and im not sure what CHP uses,but they use the callsign "H20",this guy in the EC 145 was real busy last night though....he was on the radio for atleast 20 minutes​

 

[SeanTK]

The US Military uses a variety of aircraft call-signs for various flights, and it seems to be more prevalent over saying "Army ###, ..." or "Air Force ###, ..." etc etc.

I've personally heard Jedi, Casino, and Sabre.

Here is an explanation and listing of callsigns used. Note that this is a few years old, and that callsign usage constantly changes:
http://monitoringtimes.com/MilitaryCallsignList-APR09.pdf