Mason
This extension can simplify the rule to just specify the URI and Content type and can enable/disable each rule separately. What's more, it can customize the web pages by user scripts which is similar to Grease Monkey.
RefControl
RefControl is an extension for Firefox that lets you control what gets sent as the HTTP Referer on a per-site basis.
This can ...
Referer Control
Referer Control grants full control over the HTTP Referer. You can forge any referrer you want, both globally or on a per-site ...
Smart Referer
This extension automatically hides the referer when changing domains. The domain changing is based on the same origin policy.
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