diff --git a/g10/call-agent.c b/g10/call-agent.c
index 797faf572..0416218df 100644
--- a/g10/call-agent.c
+++ b/g10/call-agent.c
@@ -352,7 +352,7 @@ start_agent (ctrl_t ctrl, int flag_for_card)
               break;
             default:
               write_status_text (STATUS_CARDCTRL, "4");
-              log_info ("selecting openpgp failed: %s\n", gpg_strerror (rc));
+              log_info ("selecting card failed: %s\n", gpg_strerror (rc));
               break;
             }
         }
@@ -729,7 +729,12 @@ learn_status_cb (void *opaque, const char *line)
 
 /* Call the scdaemon to learn about a smartcard.  Note that in
  * contradiction to the function's name, gpg-agent's LEARN command is
- * used and not the low-level "SCD LEARN". */
+ * used and not the low-level "SCD LEARN".
+ * Used by:
+ *  card-util.c
+ *  keyedit_menu
+ *  card_store_key_with_backup  (Woth force to remove secret key data)
+ */
 int
 agent_scd_learn (struct agent_card_info_s *info, int force)
 {
@@ -819,6 +824,10 @@ agent_scd_apdu (const char *hexapdu, unsigned int *r_sw)
 }
 
 
+/* Used by:
+ *  card_store_subkey
+ *  card_store_key_with_backup
+ */
 int
 agent_keytocard (const char *hexgrip, int keyno, int force,
                  const char *serialno, const char *timestamp)
@@ -848,8 +857,18 @@ agent_keytocard (const char *hexgrip, int keyno, int force,
 
 
 /* Call the agent to retrieve a data object.  This function returns
-   the data in the same structure as used by the learn command.  It is
-   allowed to update such a structure using this command. */
+ * the data in the same structure as used by the learn command.  It is
+ * allowed to update such a structure using this command.
+ *
+ *  Used by:
+ *     build_sk_list
+ *     enum_secret_keys
+ *     get_signature_count
+ *     card-util.c
+ *     generate_keypair (KEY-ATTR)
+ *     card_store_key_with_backup (SERIALNO)
+ *     generate_card_subkeypair  (KEY-ATTR)
+ */
 int
 agent_scd_getattr (const char *name, struct agent_card_info_s *info)
 {
@@ -878,6 +897,7 @@ agent_scd_getattr (const char *name, struct agent_card_info_s *info)
   return rc;
 }
 
+
 
 /* Send an setattr command to the SCdaemon.
  * Used by:
@@ -954,7 +974,10 @@ inq_writecert_parms (void *opaque, const char *line)
 }
 
 
-/* Send a WRITECERT command to the SCdaemon. */
+/* Send a WRITECERT command to the SCdaemon.
+ * Used by:
+ *  card-util.c
+ */
 int
 agent_scd_writecert (const char *certidstr,
                      const unsigned char *certdata, size_t certdatalen)
@@ -985,60 +1008,6 @@ agent_scd_writecert (const char *certidstr,
 }
 
 
-
-/* Handle a KEYDATA inquiry.  Note, we only send the data,
-   assuan_transact takes care of flushing and writing the end */
-static gpg_error_t
-inq_writekey_parms (void *opaque, const char *line)
-{
-  int rc;
-  struct writekey_parm_s *parm = opaque;
-
-  if (has_leading_keyword (line, "KEYDATA"))
-    {
-      rc = assuan_send_data (parm->dflt->ctx, parm->keydata, parm->keydatalen);
-    }
-  else
-    rc = default_inq_cb (parm->dflt, line);
-
-  return rc;
-}
-
-
-/* Send a WRITEKEY command to the SCdaemon. */
-int
-agent_scd_writekey (int keyno, const char *serialno,
-                    const unsigned char *keydata, size_t keydatalen)
-{
-  int rc;
-  char line[ASSUAN_LINELENGTH];
-  struct writekey_parm_s parms;
-  struct default_inq_parm_s dfltparm;
-
-  memset (&dfltparm, 0, sizeof dfltparm);
-
-  (void)serialno;
-
-  rc = start_agent (NULL, 1);
-  if (rc)
-    return rc;
-
-  memset (&parms, 0, sizeof parms);
-
-  snprintf (line, DIM(line), "SCD WRITEKEY --force OPENPGP.%d", keyno);
-  dfltparm.ctx = agent_ctx;
-  parms.dflt = &dfltparm;
-  parms.keydata = keydata;
-  parms.keydatalen = keydatalen;
-
-  rc = assuan_transact (agent_ctx, line, NULL, NULL,
-                        inq_writekey_parms, &parms, NULL, NULL);
-
-  status_sc_op_failure (rc);
-  return rc;
-}
-
-
 
 /* Status callback for the SCD GENKEY command. */
 static gpg_error_t
@@ -1066,10 +1035,13 @@ scd_genkey_cb (void *opaque, const char *line)
 }
 
 /* Send a GENKEY command to the SCdaemon.  If *CREATETIME is not 0,
-  the value will be passed to SCDAEMON with --timestamp option so that
-  the key is created with this.  Otherwise, timestamp was generated by
-  SCDEAMON.  On success, creation time is stored back to
-  CREATETIME.  */
+ * the value will be passed to SCDAEMON with --timestamp option so that
+ * the key is created with this.  Otherwise, timestamp was generated by
+ * SCDEAMON.  On success, creation time is stored back to
+ * CREATETIME.
+ * Used by:
+ *   gen_card_key
+ */
 int
 agent_scd_genkey (int keyno, int force, u32 *createtime)
 {
@@ -1102,9 +1074,17 @@ agent_scd_genkey (int keyno, int force, u32 *createtime)
   status_sc_op_failure (rc);
   return rc;
 }
+
+
 
 /* Return the serial number of the card or an appropriate error.  The
-   serial number is returned as a hexstring. */
+ * serial number is returned as a hexstring.  With DEMAND the active
+ * card is switched to the card with that serialno.
+ * Used by:
+ *   card-util.c
+ *   build_sk_list
+ *   enum_secret_keys
+ */
 int
 agent_scd_serialno (char **r_serialno, const char *demand)
 {
@@ -1112,7 +1092,7 @@ agent_scd_serialno (char **r_serialno, const char *demand)
   char *serialno = NULL;
   char line[ASSUAN_LINELENGTH];
 
-  err = start_agent (NULL, 1 | FLAG_FOR_CARD_SUPPRESS_ERRORS);
+  err = start_agent (NULL, (1 | FLAG_FOR_CARD_SUPPRESS_ERRORS));
   if (err)
     return err;
 
@@ -1133,8 +1113,13 @@ agent_scd_serialno (char **r_serialno, const char *demand)
   *r_serialno = serialno;
   return 0;
 }
+
+
 
-/* Send a READCERT command to the SCdaemon. */
+/* Send a READCERT command to the SCdaemon.
+ * Used by:
+ *  card-util.c
+ */
 int
 agent_scd_readcert (const char *certidstr,
                     void **r_buf, size_t *r_buflen)
@@ -1172,6 +1157,8 @@ agent_scd_readcert (const char *certidstr,
 
   return 0;
 }
+
+
 
 struct card_cardlist_parm_s {
   int error;
@@ -1209,7 +1196,12 @@ card_cardlist_cb (void *opaque, const char *line)
   return 0;
 }
 
-/* Return cardlist.  */
+
+/* Return a list of currently available cards.
+ * Used by:
+ *   card-util.c
+ *   skclist.c
+ */
 int
 agent_scd_cardlist (strlist_t *result)
 {
@@ -1238,16 +1230,20 @@ agent_scd_cardlist (strlist_t *result)
 
   return 0;
 }
+
+
 
 /* Change the PIN of an OpenPGP card or reset the retry counter.
-   CHVNO 1: Change the PIN
-         2: For v1 cards: Same as 1.
-            For v2 cards: Reset the PIN using the Reset Code.
-         3: Change the admin PIN
-       101: Set a new PIN and reset the retry counter
-       102: For v1 cars: Same as 101.
-            For v2 cards: Set a new Reset Code.
-   SERIALNO is not used.
+ * CHVNO 1: Change the PIN
+ *       2: For v1 cards: Same as 1.
+ *          For v2 cards: Reset the PIN using the Reset Code.
+ *       3: Change the admin PIN
+ *     101: Set a new PIN and reset the retry counter
+ *     102: For v1 cars: Same as 101.
+ *          For v2 cards: Set a new Reset Code.
+ * SERIALNO is not used.
+ * Used by:
+ *  card-util.c
  */
 int
 agent_scd_change_pin (int chvno, const char *serialno)
@@ -1281,8 +1277,11 @@ agent_scd_change_pin (int chvno, const char *serialno)
 
 
 /* Perform a CHECKPIN operation.  SERIALNO should be the serial
-   number of the card - optionally followed by the fingerprint;
-   however the fingerprint is ignored here. */
+ * number of the card - optionally followed by the fingerprint;
+ * however the fingerprint is ignored here.
+ * Used by:
+ *  card-util.c
+ */
 int
 agent_scd_checkpin  (const char *serialno)
 {
@@ -1307,15 +1306,6 @@ agent_scd_checkpin  (const char *serialno)
 }
 
 
-/* Dummy function, only used by the gpg 1.4 implementation. */
-void
-agent_clear_pin_cache (const char *sn)
-{
-  (void)sn;
-}
-
-
-
 
 /* Note: All strings shall be UTF-8. On success the caller needs to
    free the string stored at R_PASSPHRASE. On error NULL will be
diff --git a/g10/call-agent.h b/g10/call-agent.h
index 4c4fb2d4d..86ee8a170 100644
--- a/g10/call-agent.h
+++ b/g10/call-agent.h
@@ -108,10 +108,6 @@ gpg_error_t agent_scd_setattr (const char *name,
 int agent_scd_writecert (const char *certidstr,
                           const unsigned char *certdata, size_t certdatalen);
 
-/* Send a WRITEKEY command to the SCdaemon. */
-int agent_scd_writekey (int keyno, const char *serialno,
-                        const unsigned char *keydata, size_t keydatalen);
-
 /* Send a GENKEY command to the SCdaemon. */
 int agent_scd_genkey (int keyno, int force, u32 *createtime);
 
@@ -125,10 +121,6 @@ int agent_scd_change_pin (int chvno, const char *serialno);
 /* Send the CHECKPIN command to the SCdaemon. */
 int agent_scd_checkpin  (const char *serialno);
 
-/* Dummy function, only implemented by gpg 1.4. */
-void agent_clear_pin_cache (const char *sn);
-
-
 /* Send the GET_PASSPHRASE command to the agent.  */
 gpg_error_t agent_get_passphrase (const char *cache_id,
                                   const char *err_msg,
diff --git a/g10/card-util.c b/g10/card-util.c
index f4054a9fd..f9cce33ee 100644
--- a/g10/card-util.c
+++ b/g10/card-util.c
@@ -91,8 +91,6 @@ change_pin (int unblock_v2, int allow_admin)
   log_info (_("OpenPGP card no. %s detected\n"),
               info.serialno? info.serialno : "[none]");
 
-  agent_clear_pin_cache (info.serialno);
-
   if (opt.batch)
     {
       agent_release_card_info (&info);
@@ -1285,8 +1283,6 @@ check_pin_for_key_operation (struct agent_card_info_s *info, int *forced_chv1)
 {
   int rc = 0;
 
-  agent_clear_pin_cache (info->serialno);
-
   *forced_chv1 = !info->chv1_cached;
   if (*forced_chv1)
     { /* Switch off the forced mode so that during key generation we