Question about Sunday Bloody Sunday video

     Hello
      
      
     I have a Sunday Bloody sunday video that I recorded from a brazilian
     tv channel about 10 years ago. Last night I saw it and I noticed
     again some letters in the top of the screen : ZDF.
     Does anybody know what is the meaning of those letters (ZDF)??
     Perhaps it's some tv channel, I don't have idea.
     I don't know which was the location , but it's like a gig, probably of
     the Unforgettable Fire era.
      
      
     Thanks in advance!
      
      
     Marcia