As I read it,
http://bibframe.org/documentation/annotations/20130430.html attempts
to solve two problems (a) lightweight representation of
non-canonical bibliographic metadata and (b) knowing which RDF
triples should be exchanged in inter-operability processes. I
say 'As I read it' because the document appears to contain no
explicit statement of the problem(s) it is attempting to
address.
(a) I agree that a lightweight representation is likely to
be necessary, but this is not it. Introducing semantically new
RDF properties into bibframe, the current scheme introduces a
complexity burden on every bibframe-compliant tool, in
perpetuity. A very similar representation could have been
achieved by using OWL to create syntactic sugar RDF properties
(potentially in combination with selected Open
Annotation, SIOC, etc. properties, if necessary). These would
appear to users just like normal properties, but allow tools
which didn't care about them to use only the existing
properties. This would also avoid drawing an artificial line
in the sand between reviews that are Works and reviews that
aren't. Given that reviews range continuously from
stars-of-out-three to three-volume dissertations, it's hard to
imagine that every library is going to get that right every
time. Syntactic sugar RDF properties would let us treat
reviews as Works when we wanted to and only then.
(b) There is an already implemented and optimized
technology for organizing large sets of RDF triples of
divergent provenance and lifecycles, called 'Named Graphs.' As
far as I can tell it is an idea solution for dealing with the
fact that some of the content is 'core' bibliographic content
from a consortia; some is user contributed data under a custom
license; some is commercially licensed cover images; some is
harvested from wikipedia; some is local cataloging of unique
items; some is temporary cataloging of
recently received items; etc.