re:section 4.2.1 Authority Key Identifier

Peter:

We are revising this material this week and will take your comments into 
account.  I believe what you are proposing is fine.  One change we may make is 
to express the constraints on use of the various components in the form of 
comments, rather than add the extra level SEQUENCE encoding which is not really 
necessary.

Regards,
Warwick