extend with OpenSSL hint

DOCUMENTATION.md

@@ -705,7 +705,7 @@ Default:
 
 ##### protocol
 
-Accepted SSL protocol
+Accepted SSL protocol (maybe not all supported by underlying OpenSSL version)
 Example for secure configuration: ALL -SSLv3 -TLSv1 -TLSv1.1
 Format: Apache SSLProtocol list (from "mod_ssl")
 
@@ -713,7 +713,7 @@ Default: (system default)
 
 ##### ciphersuite
 
-Accepted SSL ciphersuite
+Accepted SSL ciphersuite (maybe not all supported by underlying OpenSSL version)
 Example for secure configuration: DHE:ECDHE:-NULL:-SHA
 Format: OpenSSL cipher list (see also "man openssl-ciphers")