<title>Talking to Brewster Kahle, TMC</title>
<h1>Bewster</h1>

<h2>About UDIs</h2>
Brewster and I were in general agreement about the criteria for names
and addresses (UDIs) in information space.
We had come to different conclusions about a few details, and the
actual syntax.
<p>
The most superficial difference is that Brewster's UDIs have the
most significant bit on the left (like mail addresses),
and mine have it on the right
(like numbers and filenames).
We didn't spend much time on this arbitray choice.
But it would be convenient to have it the same way.
<p>
We talked about the relationship between names and addresses.
(A name supports equality opertor and is unique and lasting;
an address indicates a particular access method).
Brester felt that addresses should always have a name attached to them,
so that one could always verify the thing they pointed to was the right
thing. Therefore, he proposes a syntax with a (name, address) pair.
I suggeted that any name may correspond to many addresses, so
wheras it might be raesonable to insist on the presence of the name,
it was reasonable to allow a list of addresses.
<p>
The W3 idea of making the name of a result set the name plus the
query was new to Brewster, and he liked it. 
This opens the quesry language can of worms in the nice clean UDI
camp.
<p>
WAIS had originally started with common LISP notation, which it still
uses for the WAIS "source" files, and later moved to something looking more
like a mail address. This was partly because Brewster was simply impressed
with the way mail addresses work so well.
<p>
A single simple quoting scheme must be defined for UDIs ideally.
<p>UDIs ideally have a distinct structure in which parts understandable
by the client, server and application are distinct.
The WAIS client allows relevant feedback to be made to a portion of a document
only, in which case the client/application builds the anchor
(in practice a range) and the server has to undersnand this.
(In fact, the server just operates in client mode to retrieve
the relevant data, so both sides are in fact clients.)
<p>NB: Commercial world interest in the UDI format
is possible from AMIX, Xanadu (?!),
NeXT, Pandora.
<h2>Other random points</h2>
occuring during discussions of of which I was reminded:
<dl>
<dt>Feezing queries
<dd>make it obvious from the UI what document is
a "live" query and what is a frozen copy. The same UI metaphor could
be used for "live" documents and archive copies. It is important
to know which you're linking to.
<dt>Date information
<dd>Brewster found that the only extra functionality he had
had to add to text input to queries (and relevance feedback)
was date information. People want to query by date.
Other (boolean, SQL, etc) forms of query had not been necessary.
This is interesting because date infomation is also needed for
machine-machine interaction for news (a la NNTP) and cache updating.
(If versioning is supported as a then obviously that ties in with dates.
<dt>Quoting
</dl>