standalone links and link homes

[Eric Dean Tribble <tribble>]

Nothing in our current semantics prevents standalone link objects (or
anything else, for that matter).  Since we have document types, the
document type at the top level of the work will simply be link.  Big
Deal.  Same for standalone Ends.  I think such things should be
carefully considered!  Notice for example that you'd really like
document description stuff for standalone links (who's the author?).

I think the convention for where a link makes its home will evolve
with the link type.  For example, I expect most comment and refutation
links to be stored in the comment document (the FROM end); most
formatting links to be stored in the formatted document (the TO end);
most related-to links to be in standalone documents (because both docs
are pre-existing).  Notice that the version tracking in each of the
above cases is exactly correct.  The system's going down, so I won't
show why right now.

Please list the link types that you think ought to be stand-alone.
Then we can examine whether they ought to version-track or
permission-track with any other documents.  There is NO generally
correct answer to this, only general classes of links that will evolve
with the link-types.

dean