HTTP Allowlist

Setting the policy specifies a list of hostnames or hostname patterns (such as
'[*.]example.com') that will not be upgraded to HTTPS and will not show an
error interstitial if HTTPS-First Mode is enabled. Organizations can use this
policy to maintain access to servers that do not support HTTPS, without
needing to disable HTTPS Upgrades and/or HTTPS-First Mode.

Supplied hostnames must be canonicalized: Any IDNs must be converted to their
A-label format, and all ASCII letters must be lowercase.

Blanket host wildcards (i.e., "*" or "[*]") are not allowed. Instead,
HTTPS-First Mode and HTTPS Upgrades should be explicitly disabled via their
specific policies.

Note: This policy does not apply to HSTS upgrades.

Example value:

testserver.example.com
[*.]example.org