"proxy tasks" request is not documented in https://www.zabbix.com/documentation/current/en/manual/appendix/protocols/server_proxy .

Zabbix server seems to use that command for passive proxies every second if ProxyDataFrequency is set to higher value than the default of 1.

This is missing at least in Zabbix 7.0 documentation, but please add it to the other versions as well where relevant.

Sample capture is attached.