remote commands in action operations have "Zabbix server" and "Zabbix server (proxy)" among the "execute on" options.

while a careful observer could figure out what these are, it would be useful to document that in detail - was unable to spot this in either of these pages :

• https://www.zabbix.com/documentation/4.0/manual/config/notifications/action/operation/remote_command
• https://www.zabbix.com/documentation/4.0/manual/web_interface/frontend_sections/configuration/actions