[Open Annotation] some questions

Dear Robert, all,

as you suggested...here I'am with asking for some clarifications :-)

1) We are using xpointers and would like to model using Fragment Selectors,
however we also would like to support different kinds of media fragments
(e.g. video, images, etc.). So we would need to have specializations as
subclasses of oa:FragmentSelector, e.g. pundit:XPointerFragmentSelector

2) Instead of having FragmentSelectors as resources wouldn't it make sense
to model like this ?
:fragment :hasXPointerFragmentSelector "fragment" .
:fragment :hasSource <http://exmaple.org/page1.html> .
It would be a more compact representation and I see no big drawbacks.

3) Is there a standard way to represent collections of annotations (in
Pundit we are calling them notebooks)? Should I use ORE Aggregations? I'm
not sure it is exactly what I need.. do you know if someone faced this
issue?

4) In Pundit we assume a web page can include what we call "named
contents", that are atomic, granular pieces of content that can have
identifiers ( resolvable URLs). Think about a page that is divided in
paragraphs. A web representation of that page can include a number of
paragraphs and explicitly mark them up specifying identifiers (URLs) for
each of them. Then you could have a different page where some of the
paragraphs appears, perhaps mixed with other content (e.g. commentary, or
text taken from other sources, etc.). You can read more at
http://thepund.it/client.php under "Play nice with Pundit".
In practice we are using such named contents as targets of our annotations
(instead of the URL of the enclosing web page), so that we are able to show
annotations in whatever web page includes those named contents, and
furthermore, allows us to correctly display the annotation even if the HTML
around a named content changes. However, we also want an annotation to
remember the enclosing web page (containing the named content) where it has
been created. To this end we are using a pundit:hasPageContext relation.
... I know this is a bit tricky and I hope I succeeded in explaining it :-)
Do you think this could be relevant to open annotation?

best,

Christian