$to is a modifier that's applied to the request URL's domain name:
https://adguard.com/kb/general/ad-filtering/create-own-filters/#to-modifier
$from is just an alias for $domain
I am not entirely sure that $to can be implemented in Safari content blockers though, if-domain may only be applied to the main document domain, needs to be tested.
UPD: quick test shows that if-domain won't work indeed. Anyways, let's keep this issue open, maybe you can come up with an alternative solution.
UPD2: for $to I suggest using if-frame-url, but we should keep in mind that it cannot be mixed with any unless-* property.
$tois a modifier that's applied to the request URL's domain name:https://adguard.com/kb/general/ad-filtering/create-own-filters/#to-modifier
$fromis just an alias for$domainI am not entirely sure that
$tocan be implemented in Safari content blockers though,if-domainmay only be applied to the main document domain, needs to be tested.UPD: quick test shows that
if-domainwon't work indeed. Anyways, let's keep this issue open, maybe you can come up with an alternative solution.UPD2: for
$toI suggest usingif-frame-url, but we should keep in mind that it cannot be mixed with anyunless-*property.