Comments on draft-adid-urn-00

[[e-mail] (Dale R. Worley)]

Here are a bunch of comments on draft-adid-urn-00.  Overall the concept
seems fine, but the document needs cleaning up.

The title contains "Adverting".  Have you run the draft through a
spelling checker?

      The following is an example of an Ad-ID Identifier in its
      canonical representation:

             ABCD0001000

      The canonical URN representation of the same Ad-ID Identifier is:

         urn:adid:ABCD0001000
         urn:adid:ABCD0001000H


      The 32-bit unique representation of the Ad-ID is:

         urn:adid:cuid:36faeaba

This example is difficult to follow.  The first item is
straightforward, as it is an 11 character string.  But the next item
isn't clear:  by definition, a "canonical" representation is one
representation chosen from among many.  You can say that both

         urn:adid:ABCD0001000
         urn:adid:ABCD0001000H

are URN representations of the Ad-ID identifier, but only one of them
can be canonical.  Also, it would be helpful if you explained why both
URNs correspond to ABCD0001000, or at least provide a reference to
some description which will explain it.

But, reading http://www.ad-id.org/how-it-works/ad-id-structure, it
seems that ABCD0001000H is not the *same* Ad-ID as ABCD0001000, but
rather the Ad-ID for the corresponding High Definition version of the
asset.  You need to clarify this so that the example is not
misleading.

It is not clear how the further "32-bit unique representation"
corresponds to the preceding three representations.  It's reasonably
clear what "32-bit" means as the URN contains a sequence of 8 hex
digits, but it's completely unclear what is "unique" about it.

Remember, this is the introduction, which should be readable by people
who don't already understand the technology, including people who
don't already understand Ad-IDs in all their forms.

There's some general trouble about the indentation of text.  For
instance, it seems that "The identifier structure is as follows:"
should be 4 spaces to the left, "Non alphanumeric ("special")
characters and spaces are not valid within an Ad-ID." should have a
blank like above it and be moved 3 spaces to the left, and "A
Canonical Full Ad-ID ..." should be moved 1 space to the left.

This text has some redundancy that should be removed:

          A Canonical Full Ad-ID Identifier shall conform to the syntax
          specified below using ABNF (as specified in IETF RFC 5234):
          The URN representation URN-ADID of an Ad-ID Identifier
          conforms to the syntax (expressed using ABNF (as specified in
          [RFC5234]):

The production

          adid_prefix = (ALPHA / %x30-39) 4*alphanum
               ; first character not zero

is incorrect on two counts:  As written, the first character can be
zero (which ix %x30).  The strings generated are 5 characters.  What
you want is

          adid_prefix = (ALPHA / %x31-39) 3*alphanum
               ; first character not zero

The instances of ALPHA and DIGIT might be intended to be "alpha" and
"digit".  Or do you mean to reference the productions ALPHA and DIGIT
in RFC 5234?  If so, you should eliminate the productions for "alpha"
and "digit" in the draft.

The BNF does not show how the "urn:adid:cuid" URNs are generated.  As
the BNF now stands, those examples are invalid.

      Ad-ID URNs are resolved via URN resolvers run under Ad-ID's
      responsibility.

It would be helpful here to provide a pointer to the documentation for
the resolvers.

      The validity of an URN-ADID can be checked using Ad-ID's web
      services.

Ditto.

Dale