Documentation / technical / api-xdiff-interface.txton commit check-ref-format doc: de-emphasize the implementation detail of a ref (a0a7e9e)
   1xdiff interface API
   2===================
   3
   4Talk about our calling convention to xdiff library, including
   5xdiff_emit_consume_fn.
   6
   7(Dscho, JC)