This is a loadmodule command issued on a global scale. That is, all IRC servers will attempt to load this module at the same time. Extreme caution is urged with this command. You must specify a module that exists on all servers or you will cause a netsplit.
This command takes one argument, the module to be loaded. This is usually in the format of the module file name. For instance, to load the GNUTLS module on all servers, this command can be used:
Generally, you do not want to issue this command at all. Server owners should instead load the modules manually through IRC server configuration files. After that has been taken care of, a rehash command can be issued to reload the modules network wide then.