diff --git a/src/or/or.h b/src/or/or.h
index e246ac42e2..2acb621014 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -2611,11 +2611,24 @@ typedef struct origin_circuit_t {
    * according to our current circuit-build timeout, but which has
    * been kept around because it might still succeed in connecting to
    * its destination, and which is not a fully-connected rendezvous
-   * circuit. */
+   * circuit.
+   *
+   * (We clear this flag for client-side rendezvous circuits when they
+   * are 'joined' to the other side's rendezvous circuit, so that
+   * connection_ap_handshake_attach_circuit can put client streams on
+   * the circuit.  We also clear this flag for service-side rendezvous
+   * circuits when they are 'joined' to a client's rend circ, but only
+   * for symmetry with the client case.  Client-side introduction
+   * circuits are closed when we get a joined rend circ, and
+   * service-side introduction circuits never have this flag set.) */
   unsigned int hs_circ_has_timed_out : 1;
 
   /** Set iff this is a service-side rendezvous circuit for which a
-   * new connection attempt has been launched. */
+   * new connection attempt has been launched.  We consider launching
+   * a new service-side rend circ to a client when the previous one
+   * fails; now that we don't necessarily close a service-side rend
+   * circ when we launch a new one to the same client, this flag keeps
+   * us from launching two retries for the same failed rend circ. */
   unsigned int hs_service_side_rend_circ_has_been_relaunched : 1;
 
   /** What commands were sent over this circuit that decremented the