ABI / ivars policy

[Quentin Mathé]

Hi,

Is there now an official policy that explains how we handle ivar  
addition/removal? Is it still ok to put them in the header?
I remember to have read a lengthy discussion on this topic few months  
ago, and I just added some ivars to NSTableColumn, so I was wondering  
whether what I did was correct or not.

Cheers,
Quentin.