If you put a ? in front of the command, it will prompt.
I had composed this answer, before I saw that Charlie Brown had also answered:
You could just precede the command with a question mark, like this: ?DSPUSRPRF
Or you could use two question marks in front of the appropriate keyword, to prompt for specific parameters: DSPUSRPRF ??USRPRF(&User1) ??TYPE(*ALL). This would insert the value of the &User1 variable into the USRPRF parameter and replace the default value for TYPE with *ALL, and then prompt for both parameters, so that the user could change their values if desired.
If basic command and parameter prompting is what’s wanted, then the Information Center has lots of details. You can review all of the rules under <a href=”http://publib.boulder.ibm.com/infocenter/iseries/v5r4/index.jsp?topic=/rbam6/allow.htm”>Prompting for user input at run time</a>. You might pay special attention to the “Using selective prompting for CL commands” sub-topic.
Prompt control can be almost a programming ‘language’ all by itself.