The tree conflict WC APIs:
svn_wc_get_tree_conflict
svn_wc_add_tree_conflict
should be private to Subversion, because (a) tree conflict support is expected
to change significantly during the v1.6.0 to v1.7.0 time frame, and it might be
hard to maintain support for these APIs; and (b) there seems to be little need
for a third-party project to access the WC APIs rather than the client APIs, and
little chance if there is such a project that it would be unable to use the
private APIs.
See this email thread: <http://svn.haxx.se/dev/archive-2008-11/0384.shtml>.