diff --git a/doc/src/sgml/fdwhandler.sgml b/doc/src/sgml/fdwhandler.sgml
index 25832d227f..17e17233fe 100644
--- a/doc/src/sgml/fdwhandler.sgml
+++ b/doc/src/sgml/fdwhandler.sgml
@@ -415,7 +415,9 @@ GetForeignUpperPaths(PlannerInfo *root,
      currently being considered.  <literal>output_rel</literal> is the upper relation
      that should receive paths representing computation of this step,
      and <literal>input_rel</literal> is the relation representing the input to this
-     step.  The <literal>extra</literal> parameter provides additional details,
+     step.  Pushdown of sorts by <literal>UPPERREL_ORDERED</literal>
+     should guarantee that remote sort ordering matches local ordering.
+     The <literal>extra</literal> parameter provides additional details,
      currently, it is set only for <literal>UPPERREL_PARTIAL_GROUP_AGG</literal>
      or <literal>UPPERREL_GROUP_AGG</literal>, in which case it points to a
      <literal>GroupPathExtraData</literal> structure;