a couple more thoughts about ccpp.txt

1. Perhaps it would be reasonable to split the ccpp.txt document into
   two separate documents. One to deal with specific W3C CC/PP
   issues. I think these would be primarily XML encoding issues. The
   second document could deal with extensions to the algebra. This
   would include defaults, etc.

2. I was puzzled reading section 2. I would have thought that both
   parties would need to know the tags (similar to how both parties
   involved in network communication have to understand the protocol
   headers) or confusion would reign.

3. Section 2.3 mentions two consequences of the need for content
   negotiation. The first I understand. But I don't see how the second
   consequence is derived for the discussion in section 2.

4. Section 3.2 describes a message transmission model that
   appears reduce to a two party communication channel. (S) is the
   message sending system and (R) is the receiving system. I don't
   believe this is necessarily true, when there are other sources of
   profile data such as Vendor supplied default values.

5. Sometimes the interaction between client and server is long
   lived. The value associated with some features may change.
   For example, the user may turn sound on or off. To signal this
   change we could send the entire profile or we could send just
   the information associated with the change.

   I am unclear on how things, except for specific features, are named
   in the CONNEG algebra. What if we are dealing with a Mac and there
   are two displays? What if I change the characteristics of the
   display? How do I name the specific feature, for example - color,
   that I have changed?

   Named predicates might work, but I am unclear on the
   concept. Consider a sample VGA description:

   (SONY_VGA_MODELXXX) :-
      (| (& (pix-x=640)
            (pix-y=280)
            (color=256))
         (& (pix-x=1028)
            (pix-y=1028)
            (color=256)))

    There are apparently two VGA modes, but they aren't named. If I
    want to change the value of the color feature in the second mode,
    do I have to send the entire predicate?

Franklin Reynolds
Nokia Research Center