diff --git a/proto/rpki/Doc b/proto/rpki/Doc
index 5c7aa571..69796903 100644
--- a/proto/rpki/Doc
+++ b/proto/rpki/Doc
@@ -1 +1,6 @@
 S rpki.c
+S packets.c
+S rtr.c
+S transport.c
+S tcp_transport.c
+S ssh_transport.c
\ No newline at end of file
diff --git a/proto/rpki/packets.c b/proto/rpki/packets.c
index f057360f..9f00ee5f 100644
--- a/proto/rpki/packets.c
+++ b/proto/rpki/packets.c
@@ -505,7 +505,7 @@ rtr_check_receive_packet(struct rpki_cache *cache, void *pdu, const size_t len)
   // 16 = unknown pdu version
   int error = RTR_SUCCESS;
 
-  //header in hostbyte order, retain original received pdu, in case we need to detach it to an error pdu
+  // header in hostbyte order, retain original received pdu, in case we need to detach it to an error pdu
   struct pdu_header header;
   memcpy(&header, pdu, sizeof(header));
   rtr_pdu_header_to_host_byte_order(&header);
@@ -517,7 +517,7 @@ rtr_check_receive_packet(struct rpki_cache *cache, void *pdu, const size_t len)
     return RTR_ERROR;
   }
 
-  // Do dont handle error PDUs here, leave this task to rtr_handle_error_pdu()
+  // Do not handle error PDUs here, leave this task to rtr_handle_error_pdu()
   if (header.ver != rtr_socket->version && header.type != ERROR)
   {
     // If this is the first PDU we have received -> Downgrade.
diff --git a/proto/rpki/rpki.c b/proto/rpki/rpki.c
index 07404168..f8e4685e 100644
--- a/proto/rpki/rpki.c
+++ b/proto/rpki/rpki.c
@@ -3,13 +3,18 @@
  *
  *	(c) 2015 CZ.NIC
  *
- *	Using RTRLib: http://rpki.realmv6.org/
+ *	Using RTRlib: http://rpki.realmv6.org/
  *
  *	Can be freely distributed and used under the terms of the GNU GPL.
  */
 
 /**
- * DOC: The Resource Public Key Infrastructure (RPKI) to Router Protocol
+ * DOC: RPKI to Router Protocol
+ *
+ * The Resource Public Key Infrastructure (RPKI) to router protocol implementation
+ * is based on the RTRlib (http://rpki.realmv6.org/). The BIRD takes over
+ * |packets.c|, |rtr.c|, |transport.c|, |tcp_transport.c| and |ssh_transport.c| files
+ * from RTRlib.
  */
 
 #undef LOCAL_DEBUG
@@ -259,11 +264,12 @@ rpki_free_cache(struct rpki_cache *cache)
   mb_free(cache->rtr_socket->tr_socket);
   mb_free(cache->rtr_socket);
 
+  /* timers */
   tm_stop(cache->retry_timer);
   tm_stop(cache->refresh_timer);
   tm_stop(cache->expire_timer);
-
   rfree(cache->retry_timer);
+
   rfree(cache->refresh_timer);
   rfree(cache->expire_timer);
 
diff --git a/proto/rpki/rpki.h b/proto/rpki/rpki.h
index 9069c9a4..4df0c052 100644
--- a/proto/rpki/rpki.h
+++ b/proto/rpki/rpki.h
@@ -3,7 +3,7 @@
  *
  *	(c) 2015 CZ.NIC
  *
- *	Using RTRLib: http://rpki.realmv6.org/
+ *	Using RTRlib: http://rpki.realmv6.org/
  *
  *	Can be freely distributed and used under the terms of the GNU GPL.
  */
@@ -53,7 +53,7 @@ struct rpki_cache {
   node n;
   struct rpki_proto *p;
   struct rpki_cache_cfg *cfg;
-  struct rtr_socket *rtr_socket;	/* RTRLib's socket data structure */
+  struct rtr_socket *rtr_socket;	/* RTRlib's socket data structure */
   sock *sk;				/* BIRD's socket data structure */
   timer *retry_timer;			/* Timer for Cache server */
   timer *refresh_timer;			/* Timer for Cache server */
diff --git a/proto/rpki/rtr.c b/proto/rpki/rtr.c
index 5f8fd5bd..f27158d3 100644
--- a/proto/rpki/rtr.c
+++ b/proto/rpki/rtr.c
@@ -67,7 +67,7 @@ rtr_purge_records_if_outdated(struct rpki_cache *cache)
   if ((rtr_socket->last_update + rtr_socket->expire_interval) < now)
   {
     pfx_table_src_remove(cache);
-    CACHE_TRACE(D_EVENTS, cache, "Remove outdated records from pfx_table");
+    CACHE_TRACE(D_EVENTS, cache, "All ROA records from %s expired", get_cache_ident(cache));
     rtr_socket->request_session_id = true;
     rtr_socket->serial_number = 0;
     rtr_socket->last_update = 0;
@@ -162,7 +162,7 @@ rpki_refresh_hook(struct timer *tm)
 
     case RTR_CONNECTING:
     case RTR_SYNC:
-      /* Wait small amout of time to transite state */
+      /* Wait a small amount of time to the end of transitive state */
       tm_start(tm, 1);
       break;