PF flow diagram - where is it?

[Ralph Forsythe <rforsythe@centerone.com>]

I can't seem to find the post in the archives, but I recall someone making
a flow diagram (might have been ASCII, but I think it was a .gif or
something) for PF.  Unless it is identical to the IPF version at:
  http://coombs.anu.edu.au/~avalon/ipfil-flow.html
Could someone point me in the right direction?  I seem to recall some
subtle differences between the two, but I just can't remember.

Thanks!
- Ralph