Within Silverline, there are multiple address ranges that are 'Restricted' - meaning that they cannot be added as denylist entries, or use them for proxy backends, etc.
Those addresses are as follows:
"0.0.0.0/8",
"10.0.0.0/8",
"127.0.0.0/8",
"128.0.0.0/16",
"172.16.0.0/12",
"169.254.0.0/16",
"191.255.0.0/16",
"192.0.0.0/24",
"192.0.2.0/24",
"192.168.0.0/16",
"198.18.0.0/15",
"223.255.255.0/24",
"224.0.0.0/4",
"240.0.0.0/4",
"::/96",
"::/128",
"::1/128",
"::ffff:0:0/96",
"::224.0.0.0/100",
"::127.0.0.0/104",
"::255.0.0.0/104",
"0000::/8",
"0200::/7",
"3ffe::/16",
"2001:fe::1/128",
"2001:db8::/32",
"2002:e000::/20",
"2002:7f00::/24",
"2002:0000::/24",
"2002:ff00::/24",
"2002:0a00::/24",
"2002:ac10::/28",
"2002:c0a8::/32",
"fc00::/7",
"fe80::/10",
"fec0::/10",
"ff00::/8"