Ah yes. I should have worked that out myself, from here...
��� ProtoObject>>pointsTo:
��� ��� ^ (self instVarsInclude: anObject) or: [ ^self class == anObject]

for example
�� { nil } pointsTo: nil�� "--> true"

thanks Yuriy.
cheers -ben

Yuriy Tymchuk wrote: 
All �uninitialised� variables are pointing to nil. I think this is the case

Uko

On 03 Sep 2014, at 06:10, Ben Coman <btc@openinworld.com> wrote:

  
I am curious... what does it mean that
  nil PointersTo size  is a large number? Intuitively I'd have thought the answer would be zero.

Pharo build 40196 -->  ~101,000
Pharo build 30856 -->  ~103,000
Pharo build 20628 -->  ~80,000
Squeak 4.5 -->  ~40,000

cheers -ben