normal wear at a PCCB (997 Turbo)
the embedded carbon fibres in the wear layer are burnt out and the remaining muldings can be seen

delamination at a Audi CCB 2. generation
this is caused by a bad compound between base layer and wear layer. finally segments from the wear layer falling out of the surface
delamination at a PCCB 3. generation
caused by a bad compound between base layer and wear layer which leads to surface break-out
cracks at the insert holes for the floaters
caused by corroded floaters which leads to torque overrun who cracks the disc at this place