Why didn't DD reveal Voldemort's identity?

[Zara]

No: HPFGUIDX 186815

Robert A. Rosenberg:
> I may be wrong but I think the speaking of his name allows him to be 
> aware of you and what you are saying. Thus the ban is by those who do 
> not want him to tune in on them. If you are a DE there is no reason 
> to avoid saying his name. Only those who are opposed to him or are 
> scared of coming to his attention would have reason to avoid saying 
> his name.

Zara:
I can't recall of a single Death Eater that refers to Voldemort by that name. A point is made that Severus does not, but of course he would fit into your theory. However, in that scene Harry notes that the term Severues uses ("Dark Lord") is the one Death Eaters use. This seems correct. Crouch, Jr., Bella, Lucius, and Narcissa also use this name when speaking of him.