Suppress output of variables substitution in sqlplus

SET VERIFY OFF does suppress the parameter substitution dialogue, but it does not prevent the parameter entry (Enter value for..) chatter from being written to output.

However if you combine that with SET HEADING OFF you will have output that includes only return data with no garbage at the top.

I use this when I need to have a sqlplus program return XML output to an Oracle concurrent request.

SET VERIFY OFF is the answer.