Preferences to set from about:config.
Some of these might be able to be configured more ergonomically using policies.
When this option is in use, Firefox will inform you that "your browser is managed by your organisation". That message appears because NixOS installs what you have declared here such that it cannot be overridden through the user interface. It does not mean that someone else has been given control of your browser, unless of course they also control your NixOS configuration.
Declarations
Type
attribute set of (boolean or signed integer or string)Default
{ }