Feature to disable/configure HTTP Referrer-Policy

[emanruse]

Prerequisites

• I performed a cursory search of the issue tracker to avoid opening a duplicate issue
  • I also searched the existing issues at https://github.com/gorhill/uMatrix/issues
• This is not a support issue or a question
• I tried to reproduce the issue when...
  • uMatrix is the only extension
  • uMatrix with default lists/settings
  • using a new, unmodified browser profile
• I am running the latest version of uMatrix
• I checked the documentation to understand that the issue I report is not a normal behavior
• I used the logger to rule out that the issue is caused by my ruleset

Description

This is a feature request
Please make it possible to disable/configure HTTP Referrer-Policy for better privacy when navigating between websites.

A specific URL where the issue occurs

Any navigation from one web page/site which has no explicitly restrictive Referrer-Policy in HTTP headers to another.

Steps to Reproduce

1. Visit a website (site1) which has no Referrer-Policy
2. Click an external link to visit site2.

Ruleset

Irrelevant to the issue.

Supporting evidence

The HTTP headers and the logs of site2 reveal that the visit is from site1.

Your environment

• uMatrix version: 1.3.16
• Browser Name and version: Chromium 72.0.3626.122 (64 bit)
• Operating System and version: openSUSE Leap 15.0

[emanruse]

Note: I am aware of the --no-referrers command line option of Chrome but it blocks all referrers completely which does not improve privacy but in fact is an abnormal setting which increases the ability for fingerprinting.

[uBlock-user]

gorhill did float the idea -- #78 (comment)