This extension automatically hides the referer when changing domains.
The domain changing is based on the same origin policy.
Strict Mode: When enabled, Smart Referer will treat different subdomains as being different websites. Therefore a.example.com & b.example.com won't be able to see each other's referer. In general this often causes issues & results in little to no privacy improvement, we therefore highly recommended leaving this disabled. More Info »
Exceptions: A list of different source & destination hosts that should never have their referer changed. For instance a rule with Source * & Destination *.example.com will pass referers of all websites to any resource served at example.com (including its subdomains).
Whitelist Sources: An list of documents containing additional whitelist rules. The default whitelist tries to minimize the impact of his extension on everyday web surfing while still providing the maximum referer privacy possible under these circumstances. This may not be what you want. Misbehaviour in the face of spoofed referers is also not that common anymore, so most users should not experience any issues by disabling this feature entirely.
Rewrite Mode: Can be used to change what is sent to the server instead of the original referer header. The default (Send the URL you're going to as referer) is known to cause the least issues on most sites & is therefore recommended.
A website isn't working, what should I do?
If a website isn't working properly the first thing you can try is making sure strict mode is disabled.
If the issue isn't solved, you can try adding an exeception for the domain by adding the source *.<domain.name> & the destination *. Allowing www.example.com to access everything with the orignal referer you would therefore add *.example.com as the source & * as the destination.
If you want to help finding a reasonable whitelist entry that solves the issue for everyone, see this Wiki entry: https://tiny.cc/smart-referer-whitelist