* subversion/include/svn_repos.h
(svn_repos_begin_report3): Document the limited implementation
of 'svn_copyfrom_args'.
@@ -1036,7 +1036,10 @@ svn_repos_hooks_setenv(svn_repos_t *repos,
*
* @a send_copyfrom_args instructs the driver to send 'copyfrom'
* arguments to the editor's add_file() and add_directory() methods,
- * whenever it deems feasible.
+ * and therefore to send their content as deltas against the copy source,
+ * whenever it deems feasible. The implementation only does so for
+ * add_file(), and only when the file itself is the copy root (not when
+ * the file is part of a copied subtree).
*
* Use @a authz_read_func and @a authz_read_baton (if not @c NULL) to
* avoid sending data through @a editor/@a edit_baton which is not
