Tank Park Salute (Billy Bragg song)

In his song about his father’s death, Billy Bragg ends with offering up a “tank park salute” (also the name of the song). What is that? Does it have a particular UK meaning?

I’m listening to this right now, and I remembered reading a thread about the meaning. Too bad no one was able to answer it the first time around.

Anyone?

No obvious meaning springs to mind. A cursory web search suggests that many fans believe it meant something only to Bragg and his father.

I seem to recall an interviewer asking him what it meant only to get the reply “that’s between me and my Dad”.