+`Default` determines whether or not pop-up windows are allowed by default.
+
+`Locked` prevents the user from changing pop-up preferences.
+
+**Compatibility:** Firefox 60, Firefox ESR 60\
+**CCK2 Equivalent:** `permissions.popup`\
+**Preferences Affected:** `dom.disable_open_during_load`
+
+#### Windows (GPO)
+```
+Software\Policies\Mozilla\Firefox\PopupBlocking\Allow\1 = "https://example.org"
+Software\Policies\Mozilla\Firefox\PopupBlocking\Allow\2 = "https://example.edu"
+Software\Policies\Mozilla\Firefox\PopupBlocking\Default = 0x1 | 0x0
+Software\Policies\Mozilla\Firefox\PopupBlocking\Locked = 0x1 | 0x0
+```
+#### Windows (Intune)
+OMA-URI:
+```
+./Device/Vendor/MSFT/Policy/Config/Firefox~Policy~firefox~Popups/PopupBlocking_Allow
+```
+Value (string):
+```
+<enabled/>
+<data id="Permissions" value="1https://example.org2https://example.edu"/>
+```
+OMA-URI:
+```
+./Device/Vendor/MSFT/Policy/Config/Firefox~Policy~firefox~Popups/PopupBlocking_Default
+```
+Value (string):
+```
+<enabled/> or <disabled/>
+```
+OMA-URI:
+```
+./Device/Vendor/MSFT/Policy/Config/Firefox~Policy~firefox~Popups/PopupBlocking_Locked
+```
+Value (string):
+```
+<enabled/> or <disabled/>
+```
+#### macOS
+```
+<dict>
+ <key>PopupBlocking</key>
+ <dict>
+ <key>Allow</key>
+ <array>
+ <string>http://example.org</string>
+ <string>http://example.edu</string>
+ </array>
+ <key>Default</key>
+ <true/> | <false/>
+ <key>Locked</key>
+ <true/> | <false/>
+ </dict>
+</dict>
+```
+#### policies.json
+```
+{
+ "policies": {
+ "PopupBlocking": {
+ "Allow": ["http://example.org/",
+ "http://example.edu/"],
+ "Default": true | false,
+ "Locked": true | false
+ }
+ }
+}
+```
+### Preferences
+Set and lock preferences.
+
+**NOTE** On Windows, in order to use this policy, you must clear all settings in the old **Preferences (Deprecated)** section.
+
+Previously you could only set and lock a subset of preferences. Starting with Firefox 81 and Firefox ESR 78.3 you can set many more preferences. You can also set default preferences, user preferences and you can clear preferences.
+
+Preferences that start with the following prefixes are supported:
+```
+accessibility.
+app.update.* (Firefox 86, Firefox 78.8)
+browser.
+datareporting.policy.
+dom.
+extensions.
+general.autoScroll (Firefox 83, Firefox ESR 78.5)
+general.smoothScroll (Firefox 83, Firefox ESR 78.5)
+geo.
+gfx.
+intl.
+keyword.enabled (Firefox 95, Firefox ESR 91.4)
+layers.
+layout.
+media.
+network.
+pdfjs. (Firefox 84, Firefox ESR 78.6)
+places.
+print.
+signon. (Firefox 83, Firefox ESR 78.5)
+spellchecker. (Firefox 84, Firefox ESR 78.6)
+toolkit.legacyUserProfileCustomizations.stylesheets (Firefox 95, Firefox ESR 91.4)
+ui.
+widget.
+```
+as well as the following security preferences:
+| Preference | Type | Default
+| --- | --- | ---
+| security.default_personal_cert | string | Ask Every Time
+| If set to Select Automatically, Firefox automatically chooses the default personal certificate.
+| security.insecure_connection_text.enabled | bool | false
+| If set to true, adds the words "Not Secure" for insecure sites.
+| security.insecure_connection_text.pbmode.enabled | bool | false
+| If set to true, adds the words "Not Secure" for insecure sites in private browsing.
+| security.insecure_field_warning.contextual.enabled | bool | true
+| If set to false, remove the warning for inscure login fields.
+| security.mixed_content.block_active_content | boolean | true
+| If false, mixed active content (HTTP and HTTPS) is not blocked.
+| security.osclientcerts.autoload | boolean | false
+| If true, client certificates are loaded from the operating system certificate store.
+| security.ssl.errorReporting.enabled | boolean | true
+| If false, SSL errors cannot be sent to Mozilla.
+| security.tls.enable_0rtt_data | boolean | true
+| If false, TLS early data is turned off (Firefox 93, Firefox 91.2, Firefox 78.15).
+| security.tls.hello_downgrade_check | boolean | true
+| If false, the TLS 1.3 downgrade check is disabled.
+| security.tls.version.enable-deprecated | boolean | false
+| If true, browser will accept TLS 1.0. and TLS 1.1 (Firefox 86, Firefox 78.8).
+| security.warn_submit_secure_to_insecure | boolean | true
+| If false, no warning is shown when submitting a form from https to http.
+
+
+Using the preference as the key, set the `Value` to the corresponding preference value.
+
+`Status` can be "default", "locked", "user" or "clear"
+
+* `"default"`: Read/Write: Settings appear as default even if factory default differs.
+* `"locked"`: Read-Only: Settings appear as default even if factory default differs.
+* `"user"`: Read/Write: Settings appear as changed if it differs from factory default.
+* `"clear"`: Read/Write: `Value` has no effect. Resets to factory defaults on each startup.
+
+`"user"` preferences persist across invocations of Firefox. It is the equivalent of a user setting the preference. They are most useful when a preference is needed very early in startup so it can't be set as default by policy. An example of this is ```toolkit.legacyUserProfileCustomizations.stylesheets```.
+
+`"user"` preferences persist even if the policy is removed, so if you need to remove them, you should use the clear policy.
+
+See the examples below for more detail.