What do @blocked from caddy config file?

Question

@blocked not remote_ip 198.199.121.219 198.199.121.249
       respond @blocked "Internal use only" 403
       reverse_proxy http://localhost:8097

I can't understand from docs. What do @blocked in caddyfile?

Why here is 2 @blocked?

Could be list of IPs be placed in @ like?

@allowedIP {
   remote_ip 198.199.121.219
}

@blocked not @allowedIP
respond @blocked "Access Deny" 403

But Caddy do not start with this config

How this config could be rewritten?