A proxy command is a command issued by one user on behalf of another user ID or user group. To issue proxy commands, you must first select a user proxy. PROC SPDO provides several interactive statements to enable you to list and select from the available user proxies. Separate statements are available for non-locking and locking user proxies. The LIST USERS statement is used in conjunction with the SET USER statement to set the context for executing a proxy command. The LIST USERS statement identifies the non-locking user proxies that are active in the connected domain so that the SET USER statement can be used to connect to one.