diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index 63cf2f8..f405065 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -1495,8 +1495,8 @@
 
 
 /**
- * \brief             Configure the use of the Connection ID (CID) extension
- *                    in the next handshake.
+ * \brief             (STUB) Configure the use of the Connection ID (CID)
+ *                    extension in the next handshake.
  *
  *                    Reference:
  *                    https://tools.ietf.org/html/draft-ietf-tls-dtls-connection-id-04
@@ -1519,6 +1519,11 @@
  *                    extension in the next handshake and to set the value of
  *                    the CID to be used for incoming messages.
  *
+ * \warning           The current implementation of this API does nothing!
+ *                    It is included solely to allow review and coding against
+ *                    the new Connection CID API.
+ *                    The actual implementation will be added in the future.
+ *
  * \param ssl         The SSL context to configure. This must be initialized.
  * \param enable      This value determines whether the CID extension should
  *                    be used or not. Possible values are:
@@ -1578,9 +1583,15 @@
                          size_t own_cid_len );
 
 /**
- * \brief              Get information about the current use of the
+ * \brief              (STUB) Get information about the current use of the
  *                     CID extension.
  *
+ * \warning            The current implementation of this API does nothing
+ *                     except setting `*enabled` to MBEDTLS_SSL_CID_DISABLED!
+ *                     It is included solely to allow review and coding against
+ *                     the new Connection CID API.
+ *                     The actual implementation will be added in the future.
+ *
  * \param ssl          The SSL context to query.
  * \param enabled      The address at which to store whether the CID extension
  *                     is currently in use or not. If the CID is in use,