The RKI in Berlin counts any CV-related death, "died of" or "died with" CV.
"Died of CV" means: obvious and CV+
"Died with CV" means: tested CV+ and died and cause of death is unclear (so e.g. no car crash).
Some federal states publish only "died of" death numbers though,
but all of them are reporting the complete numbers to Berlin as required by the RKI standard, as stated above.
RKI already said German CV-death numbers are probably
underestimating,
as we don't test post mortem for the reason of forensic staff safety,
which is being debated.
All care home deaths are included, IF tested CV+ or very obvious (like in a care home outbreak).
@BlueAnorak 40-50% would surprise me, but we just don't know exactly.