sbc: doc: added note about md5 hash

doc/Readme.sbc.txt

@@ -55,6 +55,10 @@ is provided and installed to trigger the reload (through XMLRPC):
 The xmlrpc2di module must be loaded and XMLRPC control server bound to port 8090 for
 the scripts to work.
 
+For tracking file revisions and changes, the MD5 hash sum is printed on profile load and
+reload, and returned as information by the scripts and the DI management commands. An MD5
+hash to compare checksums of profile files can also be generated with the md5sum(1) tool.
+
 Alternatively, the reload functions can be accessed by json-rpc v2 if the jsonrpc module
 is loaded. The expected parameters to all functions are in a dictionary with 
    'name' :          profile name