use std::collections::HashMap;
use std::sync::OnceLock;
static PREF_EXPLANATIONS: OnceLock<HashMap<&'static str, &'static str>> = OnceLock::new();
pub(crate) fn get_preference_explanation_static(key: &str) -> Option<&'static str> {
PREF_EXPLANATIONS
.get_or_init(|| {
HashMap::from([
(
"javascript.enabled",
"Master switch to enable or disable JavaScript execution in Firefox. \
When set to true, JavaScript can run in web pages. When false, JavaScript is \
completely disabled, which may break many modern websites that rely on JavaScript \
for functionality.",
),
(
"privacy.trackingprotection.enabled",
"Enables Firefox's built-in tracking protection feature to block online trackers. \
When set to true, Firefox blocks known tracking scripts and cookies from third-party \
trackers, enhancing privacy while browsing. When false, tracking protection is disabled \
and trackers may monitor your browsing activity across websites.",
),
(
"privacy.trackingprotection.emailtracking.enabled",
"Controls Firefox's email tracking protection feature that blocks tracking pixels \
embedded in emails. When set to true, Firefox prevents email trackers from notifying \
senders when you view emails containing hidden tracking images. This feature helps \
prevent marketing and analytics companies from tracking your email viewing behavior.",
),
(
"privacy.bounceTrackingProtection.mode",
"Controls the bounce tracking protection feature that detects and blocks redirect \
trackers. Mode 1 (stateful) requires trackers to access storage before being flagged. \
Mode 2 (stateless) is more aggressive and can block trackers based purely on redirect \
behavior without requiring storage access. This feature runs in the background when \
Enhanced Tracking Protection is set to Strict mode.",
),
(
"privacy.fingerprintingProtection",
"Enables Firefox's fingerprinting protection to prevent websites from uniquely \
identifying your browser based on its characteristics. When set to true, Firefox \
obscures or randomizes information about your device, screen configuration, installed \
fonts, and other attributes that can be used to create a digital fingerprint for \
tracking purposes across different browsing sessions.",
),
(
"privacy.globalprivacycontrol.enabled",
"Enables the Global Privacy Control (GPC) signal that tells websites not to sell \
or share your personal data. When set to true, Firefox sends a universal opt-out signal \
to every website you visit, requesting that they not sell or share your browsing data \
per regulations like CCPA. Websites are not legally required to honor this signal, \
though many do respect it.",
),
(
"privacy.trackingprotection.socialtracking.enabled",
"Controls Firefox's social tracking protection feature that blocks social media \
trackers embedded in websites. When set to true, Firefox prevents social media platforms \
like Facebook, Twitter, and LinkedIn from tracking your browsing activity across \
third-party websites through embedded buttons, widgets, and like buttons.",
),
(
"browser.contentblocking.category",
"Controls Firefox's Enhanced Tracking Protection mode. Valid values are 'standard', \
'strict', and 'custom'. Standard mode blocks basic trackers in private windows only. \
Strict mode blocks all known trackers everywhere and may cause some websites to break. \
Custom mode allows granular control over which tracking protections are enabled.",
),
(
"network.trr.mode",
"Controls DNS over HTTPS (DoH) mode in Firefox. Values: 0 = DoH disabled, \
2 = Enabled with fallback (uses DoH but falls back to standard DNS if DoH fails), \
3 = Strict mode (only uses DoH; if it fails, DNS resolution fails). Mode 2 is \
recommended as it provides a good balance between privacy and reliability.",
),
(
"network.trr.uri",
"Specifies the URL of the DNS over HTTPS (DoH) server to use for encrypted DNS \
resolution. By default, Firefox uses Cloudflare's DoH service. This setting works \
in conjunction with network.trr.mode to enable encrypted DNS queries that prevent \
ISPs and network intermediaries from seeing which websites you visit.",
),
(
"doh-rollout.disable-heuristics",
"Disables Firefox's automatic network-based detection for when to enable DNS over \
HTTPS. When set to true, Firefox will not automatically enable or disable DoH based \
on network conditions. This gives users and administrators more control over DoH \
behavior rather than letting Firefox automatically decide based on network heuristics.",
),
(
"network.http.referer.disallowCrossSiteRelaxingDefault.top_navigation",
"Prevents websites from relaxing referrer policies for cross-site top-level \
navigation. When set to true, Firefox ignores permissive referrer policy directives \
like 'unsafe-url' and 'no-referrer-when-downgrade' that would otherwise expose more \
information about which site you came from. This helps prevent referrer information \
leakage and enhances privacy.",
),
(
"dom.security.https_only_mode",
"Forces all connections to websites to use secure encrypted HTTPS instead of \
unencrypted HTTP. When set to true, Firefox automatically attempts to upgrade HTTP \
connections to HTTPS. If the HTTPS connection fails, Firefox may fall back to HTTP \
after a timeout and displays a warning about the insecure connection.",
),
(
"dom.security.https_only_mode_pbm",
"Same as dom.security.https_only_mode but applies only to Private Browsing \
windows. When set to true, Firefox forces HTTPS-only mode in private browsing sessions, \
providing stronger security protection for private browsing activities.",
),
(
"privacy.query_stripping.enabled",
"Enables query parameter stripping to remove known tracking parameters from URLs \
before navigating to them. When set to true, Firefox automatically strips tracking \
parameters like utm_source, fbclid, and gclid from URLs, preventing websites and \
third parties from tracking user behavior through link decoration.",
),
(
"privacy.query_stripping.enabled.pbmode",
"Same as privacy.query_stripping.enabled but applies specifically to Private \
Browsing mode. When set to true, Firefox strips tracking parameters from URLs in \
private browsing sessions, providing enhanced privacy by removing navigational \
tracking information.",
),
(
"privacy.annotate_channels.strict_list.enabled",
"Controls whether Firefox uses a strict list to annotate and handle tracking \
channels. When set to true, Firefox applies stricter rules for identifying and \
handling tracking network connections. This is part of the state partitioning system \
that helps separate website data to prevent cross-site tracking.",
),
(
"signon.rememberSignons",
"Controls whether Firefox's built-in password manager offers to save and remember \
website logins and passwords. When set to true, Firefox will prompt to save your \
usernames and passwords when you log into websites. When set to false, Firefox will \
not offer to save any passwords, effectively disabling the password manager functionality.",
),
(
"signon.autofillForms",
"Controls whether Firefox's Password Manager automatically fills in usernames and \
passwords on login forms. When set to true, Firefox automatically populates login forms \
with saved credentials. When set to false, Firefox requires manual intervention to fill \
login forms (you must click to fill), which can improve security by preventing automatic \
credential exposure.",
),
(
"browser.startup.page",
"Controls what Firefox displays when it starts up. Values: 0 = blank page, \
1 = home page, 2 = restore previous session, 3 = resume session (similar to 2). \
This setting determines whether Firefox shows your homepage, a blank page, or restores \
your last browsing session with all open tabs when the browser starts.",
),
(
"sidebar.verticalTabs",
"Enables vertical tabs layout in Firefox's sidebar. When set to true, tabs are \
displayed vertically in the sidebar instead of horizontally at the top of the browser \
window. This makes it easier to see many tabs at once and is part of Firefox's sidebar \
revamp introduced in recent versions.",
),
(
"sidebar.revamp",
"Enables the redesigned sidebar with enhanced features and improved integration. \
When set to true, the new sidebar provides access to multiple tools, vertical tabs, \
and a more modern interface. This is part of Firefox's major UI update to the sidebar \
system.",
),
(
"browser.urlbar.suggest.quicksuggest.all",
"Controls whether Firefox displays Firefox Suggest suggestions in the address \
bar. When set to true, Firefox shows suggested websites, sponsored suggestions, and \
quick results as you type in the address bar. When set to false, these suggestions are \
disabled, providing a more traditional address bar experience.",
),
(
"datareporting.healthreport.uploadEnabled",
"Controls whether Firefox uploads health report and telemetry data to Mozilla. \
When set to false, it disables the upload of technical data, crash reports, and \
usage statistics. This setting corresponds to the 'Allow Firefox to send technical \
and interaction data' checkbox in Firefox Settings.",
),
(
"toolkit.telemetry.reportingpolicy.firstRun",
"Related to Firefox's data choices notification system. This preference is not \
present until the first run of Firefox. After the first run, it helps control whether \
telemetry reporting policy prompts are shown. Commonly set to false in privacy-focused \
configurations to disable telemetry prompts.",
),
(
"toolkit.legacyUserProfileCustomizations.stylesheets",
"Enables loading of custom CSS files (userChrome.css and userContent.css) from \
your Firefox profile folder. When set to true, Firefox loads these custom stylesheets \
on startup, allowing advanced users to customize Firefox's appearance. Must be set to \
true for userChrome.css customizations to work. Requires Firefox restart to take effect.",
),
(
"services.settings.main.*.last_check",
"Remote Settings is a Mozilla system that delivers configuration data, blocklists, \
and feature updates to Firefox without requiring a full browser update. The 'last_check' \
preferences store Unix timestamps indicating when Firefox last successfully checked for \
updates to specific Remote Settings collections. These include tracking protection lists, \
certificate revocation lists, search configurations, and other security-critical data. \
Firefox polls these regularly (typically every 24 hours) to ensure you have the latest \
protection and configuration data.",
),
(
"services.settings.last_update_seconds",
"Stores the Unix timestamp of the last successful Remote Settings update check. \
This is used by Firefox to schedule periodic updates for Remote Settings collections, \
ensuring that blocklists, certificate revocation data, and configuration updates remain \
current without requiring manual browser updates.",
),
(
"services.settings.last_etag",
"Stores the ETag (entity tag) from the last Remote Settings server response. \
This HTTP header is used for cache validation and efficient polling - Firefox sends this \
value to the server to check if any data has changed since the last check. If the ETag \
matches, the server knows Firefox already has the latest data, saving bandwidth.",
),
(
"services.settings.clock_skew_seconds",
"Measures the time difference between your local system clock and Mozilla's Remote \
Settings server clock. A large negative value indicates your clock is behind the server. \
Firefox uses this to detect and handle clock-related issues that could affect security \
checks, certificate validation, and update scheduling.",
),
(
"privacy.clearOnShutdown_v2.formdata",
"Controls whether Firefox clears form and search history when the browser closes. \
When set to true, Firefox automatically deletes information you've entered into web forms \
and search bars when you close Firefox. This is part of the updated privacy clearing system \
(v2) that provides more granular control over what data gets cleared on shutdown.",
),
(
"privacy.trackingprotection.allow_list.hasMigratedCategoryPrefs",
"Internal migration preference indicating whether the user's tracking protection allow \
list preferences have been migrated to the new Enhanced Tracking Protection category system. \
When true, the user has been transitioned from the old tracking protection system to the \
newer 'Standard/Strict/Custom' category-based system introduced in recent Firefox versions.",
),
(
"privacy.trackingprotection.allow_list.baseline.enabled",
"Controls whether the baseline tracking protection allow list is enabled. When true, \
websites on this special list are exempt from baseline tracking protections. This is used \
to whitelist websites that would break under standard tracking protection rules, allowing \
their trackers to function normally. Firefox manages this list through Remote Settings.",
),
(
"privacy.trackingprotection.allow_list.convenience.enabled",
"Controls whether the convenience tracking protection allow list is enabled. When \
true, certain third-party services that provide useful features (like embedded maps, videos, \
or comment systems) are allowed to bypass tracking protections. This helps maintain website \
functionality while still protecting privacy where possible.",
),
(
"privacy.trackingprotection.allow_list.hasUserInteractedWithETPSettings",
"Internal preference tracking whether the user has ever manually modified their Enhanced \
Tracking Protection (ETP) settings. When true, Firefox knows the user has customized their \
tracking protection preferences, which may affect how Firefox handles future ETP updates or \
prompts.",
),
(
"privacy.bounceTrackingProtection.hasMigratedUserActivationData",
"Migration preference indicating whether bounce tracking protection data has been \
upgraded from the old storage format to the new system. When true, Firefox has successfully \
migrated user activation grants and bounce tracking state to the improved tracking protection \
system.",
),
(
"privacy.sanitize.clearOnShutdown.hasMigratedToNewPrefs3",
"Internal migration flag indicating whether privacy clearing preferences have been \
migrated to the third version of the preference system. When true, the user's settings for \
clearing data on shutdown have been updated to the latest preference format used by Firefox.",
),
(
"privacy.purge_trackers.date_in_cookie_database",
"Internal timestamp tracking when Firefox last purged tracking cookies and site data \
as part of the tracker purging feature. This is used by the 'Delete Cookies and Site Data' \
functionality that automatically removes known tracking cookies and their associated site \
data at regular intervals or on shutdown.",
),
(
"privacy.purge_trackers.last_purge",
"Stores the Unix timestamp of the last time Firefox purged tracking cookies and site \
data. Firefox automatically removes known tracking cookies and their associated storage \
periodically to prevent long-term tracking. This preference records when the last purge \
operation completed successfully.",
),
(
"privacy.globalprivacycontrol.was_ever_enabled",
"Records whether the Global Privacy Control (GPC) signal has ever been enabled in \
Firefox. When true, this indicates that at some point the user activated GPC, which sends \
a universal opt-out signal to websites requesting that they not sell or share personal data. \
Firefox uses this to track historical privacy preferences.",
),
(
"extensions.webcompat.enable_shims",
"Enables Web Compatibility shims, which are code snippets that fix broken websites \
by emulating deprecated or missing web APIs. When true, Firefox applies these fixes to make \
certain websites work properly. Shims are typically used when websites rely on old browser \
features that Firefox no longer supports. Disabling this may break some websites but \
increases browser security and reduces complexity.",
),
(
"extensions.webcompat.perform_injections",
"Controls whether the Web Compatibility add-on injects custom scripts and stylesheets \
into web pages to fix compatibility issues. When true, Firefox applies site-specific patches \
to make problematic websites render and function correctly. These injections are managed by \
Mozilla's web compatibility team and updated through Remote Settings.",
),
(
"extensions.quarantinedDomains.list",
"Contains a comma-separated list of domains where Firefox restricts extension access for \
security reasons. This feature, introduced in Firefox 115, prevents extensions from running \
on sensitive websites like banking sites, payment processors, and other security-critical \
domains. The list is maintained by Mozilla and updated through Remote Settings to protect \
users from potentially malicious extensions.",
),
(
"extensions.formautofill.addresses.enabled",
"Controls whether Firefox's autofill feature can automatically fill in address information \
(street, city, postal code, country, etc.) on web forms. When true, Firefox will suggest and \
fill address details that you've previously saved. When false, address autofill is disabled, \
requiring manual entry each time.",
),
(
"extensions.formautofill.creditCards.enabled",
"Controls whether Firefox's autofill feature can automatically fill in credit card \
information on web payment forms. When true, Firefox will offer to fill saved credit card \
details (numbers, expiration dates, cardholder names). When false, credit card autofill is \
disabled for enhanced security. Note: This feature may be region-restricted.",
),
(
"extensions.pictureinpicture.enable_picture_in_picture_overrides",
"Enables Picture-in-Picture overrides that force specific video players to work with \
Firefox's PiP feature. When true, Firefox applies site-specific patches to make video players \
from websites like YouTube, Netflix, and others work in Picture-in-Picture mode even if those \
sites try to prevent it.",
),
(
"extensions.pendingOperations",
"Internal flag indicating whether there are pending extension operations that need to \
be processed, such as installs, uninstalls, updates, or migrations. When false, no extension \
operations are pending. When true, Firefox is actively working on extension-related tasks and \
may need to restart to complete them.",
),
(
"extensions.databaseSchema",
"Version number of the extensions database schema. This tracks the format version of \
Firefox's internal extension storage database. Firefox uses this to determine if migration \
is needed when upgrading to a new version that changes how extension data is stored.",
),
(
"extensions.lastAppVersion",
"Stores the version of Firefox that was running when extensions were last checked or \
updated. This is used for compatibility checking - Firefox uses it to determine if extensions \
need to be re-validated or updated after a browser upgrade.",
),
(
"extensions.lastPlatformVersion",
"Similar to extensions.lastAppVersion but specifically tracks the platform version \
(Mozilla platform) rather than the Firefox application version. Used internally for extension \
compatibility checks.",
),
(
"media.gmp-gmpopenh264.version",
"Stores the version number of the installed OpenH264 plugin. OpenH264 is Cisco's \
open-source H.264 video codec implementation that Firefox automatically downloads to enable \
H.264 video playback on websites that require this codec. This preference tracks which \
version is currently installed.",
),
(
"media.gmp-gmpopenh264.lastDownload",
"Unix timestamp indicating when Firefox last successfully downloaded or updated the \
OpenH264 plugin. Firefox periodically checks for plugin updates to ensure you have the latest \
security fixes and performance improvements.",
),
(
"media.gmp-gmpopenh264.lastUpdate",
"Similar to lastDownload, stores the timestamp of the last OpenH264 plugin update. \
Used by Firefox's plugin management system to track when updates were applied.",
),
(
"media.gmp-gmpopenh264.lastInstallStart",
"Unix timestamp recording when the last OpenH264 plugin installation began. Used \
internally for troubleshooting installation issues and tracking plugin download timing.",
),
(
"media.gmp-gmpopenh264.hashValue",
"Cryptographic hash (SHA-256) of the OpenH264 plugin files. Firefox uses this to \
verify the integrity and authenticity of the downloaded plugin, ensuring it hasn't been \
tampered with or corrupted during download.",
),
(
"media.gmp-gmpopenh264.abi",
"Stores the Application Binary Interface (ABI) identifier for the OpenH264 plugin, \
such as 'x86_64-gcc3'. This ensures the downloaded plugin matches your system architecture \
and compiler environment. Firefox uses this to download the correct plugin variant for your \
system.",
),
(
"media.gmp-manager.lastCheck",
"Unix timestamp of the last time Firefox checked for GMP (Gecko Media Plugin) updates. \
Firefox regularly checks Mozilla's servers for updates to OpenH264, Widevine DRM, and other \
media plugins to ensure you have the latest versions.",
),
(
"media.gmp-manager.lastEmptyCheck",
"Timestamp of the last GMP update check that found no available updates. Firefox uses \
this to avoid checking too frequently when no updates are available, reducing unnecessary \
network requests.",
),
(
"media.gmp.storage.version.observed",
"Internal preference tracking the version of the GMP storage system that Firefox has \
observed. Used for migrating plugin data between different storage formats when Firefox \
updates how it stores media plugin information.",
),
(
"nimbus.profileId",
"A unique identifier (UUID) assigned to your Firefox profile for Mozilla's Nimbus \
experiment system. This ID is used to target you for specific feature experiments, A/B tests, \
and staged rollouts. It allows Mozilla to track which experiment variant you should receive \
while maintaining anonymity.",
),
(
"nimbus.migrations.init-started",
"Internal counter tracking how many times Nimbus has attempted to initialize \
migrations. Used to diagnose issues with the experiment system startup and to ensure \
experiment data is properly loaded.",
),
(
"nimbus.migrations.after-store-initialized",
"Internal migration counter for operations that run after the Nimbus experiment store \
is initialized. This tracks the number of migration cycles completed to ensure experiment \
data is properly upgraded between Firefox versions.",
),
(
"nimbus.migrations.after-remote-settings-update",
"Migration counter for updates that occur after Remote Settings data is refreshed. \
This ensures experiment configurations are properly synchronized when Firefox receives \
updated experiment data from Mozilla's servers.",
),
(
"app.normandy.user_id",
"A unique identifier for your Firefox profile used by the legacy Normandy experiment \
system (predecessor to Nimbus). Normandy was Mozilla's previous system for deploying \
experiments and preference rollouts. This ID is being phased out in favor of the Nimbus \
system.",
),
(
"app.normandy.first_run",
"Indicates whether Normandy has completed its first run initialization. When false, \
Normandy's first-run logic has not yet executed. When true, the initial setup is complete. \
This preference is being replaced by the Nimbus experiment system.",
),
(
"app.normandy.migrationsApplied",
"Counter tracking how many Normandy data migrations have been applied. This records \
the migration version number, helping Firefox track which updates to the experiment system \
have been successfully applied to your profile.",
),
(
"toolkit.startup.last_success",
"Stores the Unix timestamp of the last successful Firefox startup. Firefox uses this \
to detect crashes and abnormal shutdowns. If the current startup time is much later than \
this timestamp, Firefox knows the previous session may have ended abnormally and will offer \
to restore your tabs and windows.",
),
(
"browser.startup.couldRestoreSession.count",
"Internal counter that tracks whether Firefox has a previous browsing session available \
to restore. A value of 1 or higher indicates there are saved tabs and windows from a \
previous session. Firefox uses this to determine if it should offer session restoration \
after a crash or restart.",
),
(
"browser.startup.lastColdStartupCheck",
"Unix timestamp of the last time Firefox performed a cold startup check. A cold \
startup occurs when Firefox is launched without any already-running instances. This metric \
is used for performance monitoring and optimization of browser startup times.",
),
(
"browser.sessionstore.upgradeBackup.latestBuildID",
"Stores the Firefox build ID (version number with timestamp) of the last session \
backup created during an upgrade. When Firefox updates, it backs up your current session \
so tabs can be restored if the upgrade causes issues. This preference identifies which \
version created that backup.",
),
(
"browser.migration.version",
"Records the version of the Firefox migration system that has been applied to your \
profile. When Firefox updates and changes how data is stored or organized, it increments \
this number to track which migrations have been run. This ensures your profile data is \
properly upgraded across Firefox versions.",
),
(
"doh-rollout.home-region",
"Stores your detected home region code (e.g., 'US', 'CA', 'GB') for DNS over HTTPS \
rollout purposes. Firefox automatically determines this based on your IP address and uses \
it to decide when and how to enable DNS over HTTPS. Different regions may have different \
DoH providers or rollout schedules based on local regulations and infrastructure.",
),
(
"doh-rollout.doneFirstRun",
"Indicates whether Firefox has completed the first-run DNS over HTTPS rollout logic. \
When true, Firefox has evaluated your network environment and decided whether to enable \
DoH. When false, the first-run evaluation has not yet completed.",
),
(
"browser.region.update.updated",
"Unix timestamp of the last time Firefox successfully updated its detected region \
information. Firefox periodically checks which country/region you appear to be in based \
on your IP address to provide localized search engines, certificates, and services.",
),
(
"browser.search.region",
"Stores the country/region code that Firefox uses for search localization. This affects \
which default search engine is offered and how search results are localized. Firefox updates \
this based on your detected location, but it can also be set manually in preferences.",
),
(
"toolkit.telemetry.cachedClientID",
"A unique identifier (UUID) assigned to your Firefox installation for telemetry purposes. \
This ID is used by Mozilla to count unique users and analyze usage patterns while maintaining \
anonymity. It's generated once and persisted across Firefox restarts unless telemetry is \
disabled or you reset it.",
),
(
"toolkit.telemetry.cachedProfileGroupID",
"A UUID that groups multiple Firefox profiles together for telemetry analysis. If you \
have multiple Firefox profiles on the same system, they share this profile group ID, allowing \
Mozilla to understand usage patterns across profiles while still maintaining privacy.",
),
(
"datareporting.dau.cachedUsageProfileID",
"Another unique identifier for the Daily Active User (DAU) telemetry system. This ID \
helps Mozilla track daily active users and understand engagement metrics while preserving \
user anonymity.",
),
(
"datareporting.dau.cachedUsageProfileGroupID",
"Group identifier for DAU telemetry that correlates multiple Firefox profiles. Similar \
to the profile group ID but specifically for the Daily Active User measurement system.",
),
(
"datareporting.policy.dataSubmissionPolicyNotifiedTime",
"Unix timestamp of when you were last presented with Firefox's data submission policy \
notification. This records when Firefox showed you the prompt about sending technical and \
interaction data to Mozilla. Firefox uses this to ensure policy acceptance is properly \
tracked and to avoid showing the prompt too frequently.",
),
(
"datareporting.policy.dataSubmissionPolicyAcceptedVersion",
"Records which version of Mozilla's data submission policy you have accepted. This \
number increments when the policy changes significantly. Firefox uses this to track whether \
you need to be presented with an updated policy notification.",
),
(
"datareporting.usage.uploadEnabled",
"Master switch for Firefox usage data upload. When false, Firefox does not upload \
usage statistics, technical performance data, or interaction metrics to Mozilla. This \
corresponds to unchecking the 'Allow Firefox to send technical and interaction data' \
option in Firefox Settings.",
),
(
"browser.download.viewableInternally.typeWasRegistered.webp",
"Indicates whether Firefox has registered the WebP image format for internal viewing. \
When true, Firefox can display WebP images natively without downloading them first. This \
preference is set when Firefox initializes its MIME type handlers for different file formats.",
),
(
"browser.download.viewableInternally.typeWasRegistered.avif",
"Indicates whether Firefox has registered the AVIF image format for internal viewing. \
When true, Firefox can display AVIF images natively. AVIF is a modern image format that \
provides better compression than JPEG or WebP. This preference tracks Firefox's capability \
to handle this format.",
),
(
"browser.uiCustomization.state",
"JSON-encoded string that stores the complete state of Firefox's toolbar and UI \
customization. This records which buttons are in which toolbars, their order, and which \
items are in the overflow menu. When you customize Firefox's interface (move buttons, \
add/remove items from toolbars), this preference is updated to remember your layout.",
),
(
"browser.uiCustomization.horizontalTabstrip",
"JSON array listing the items displayed in the horizontal tab strip (when vertical \
tabs are disabled). This controls which buttons and elements appear in the tab bar area, \
such as the new tab button, all tabs button, and tab scroll buttons.",
),
(
"sidebar.verticalTabs.dragToPinPromo.dismissed",
"Indicates whether you have dismissed the promotional tooltip about dragging tabs to \
pin them when using vertical tabs. When true, you've seen and closed this prompt, and \
Firefox won't show it again. When false, the prompt may still appear.",
),
(
"sidebar.backupState",
"JSON-encoded string storing a backup of the sidebar state including position, width, \
expanded/collapsed state, and currently active tool. Firefox uses this to restore your \
sidebar configuration between browser sessions or after crashes.",
),
(
"sidebar.main.tools",
"Comma-separated list of tools available in the Firefox sidebar. Typical values include \
'syncedtabs', 'history', 'bookmarks', and more. This controls which sidebar panels are \
accessible and in what order they appear.",
),
(
"browser.toolbarbuttons.introduced.sidebar-button",
"Migration flag indicating when the sidebar toggle button was introduced to the \
toolbar. When true, Firefox has added the sidebar button to your customization options, \
typically occurring when Firefox updates and introduces new UI elements.",
),
(
"browser.newtabpage.activity-stream.impressionId",
"A unique identifier (UUID) for tracking new tab page impressions and interactions. \
This ID is used internally by Firefox to analyze how users interact with the new tab page, \
including which features they use and how they engage with sponsored content.",
),
(
"browser.newtabpage.activity-stream.showSponsored",
"Controls whether Firefox displays sponsored (paid) shortcuts and content on the new \
tab page. When true, Firefox may show sponsored website shortcuts as part of the top sites \
section. When false, only organic (non-sponsored) sites appear based on your browsing history.",
),
(
"browser.newtabpage.activity-stream.showSponsoredTopSites",
"Specifically controls sponsored shortcuts in the Top Sites section of the new tab page. \
When true, some of the frequently-visited sites shown may be sponsored placements. When false, \
all top sites are based purely on your browsing history.",
),
(
"browser.newtabpage.activity-stream.showSponsoredCheckboxes",
"Controls whether checkboxes appear next to sponsored shortcuts allowing you to dismiss \
or hide specific sponsored content. When true, you can interact with sponsored items. When \
false, sponsored items (if shown) cannot be individually dismissed.",
),
(
"browser.newtabpage.activity-stream.showWeather",
"Controls whether Firefox displays a weather widget on the new tab page. When true, \
the new tab page shows current weather conditions and a forecast for your location. When \
false, the weather widget is hidden.",
),
(
"browser.newtabpage.activity-stream.newtabWallpapers.wallpaper",
"Stores the ID of the currently selected wallpaper for the new tab page. Firefox can \
display background images (wallpapers) on the new tab page, and this preference remembers \
which one you've chosen. Examples include 'dark-blue', 'mountain', etc.",
),
(
"browser.newtabpage.activity-stream.feeds.topsites",
"Controls whether the Top Sites section is enabled on the new tab page. When true, \
Firefox displays your most frequently visited websites for quick access. When false, this \
section is hidden, potentially reducing the usefulness of the new tab page.",
),
(
"browser.newtabpage.activity-stream.feeds.section.topstories",
"Controls whether Firefox shows recommended articles and stories in the new tab page \
(also known as Pocket or Mozilla Recommended content). When true, you'll see curated \
articles. When false, this section is disabled.",
),
(
"browser.newtabpage.storageVersion",
"Version number of the new tab page storage format. When Firefox updates how it stores \
new tab page data and preferences, this number increments to trigger migration of old data \
to the new format.",
),
(
"browser.urlbar.placeholderName",
"Stores the name of the default search engine to display in the address bar placeholder \
text. For example, 'Google' or 'Bing'. This provides visual feedback about which search \
engine will be used when you type search terms in the address bar.",
),
(
"browser.urlbar.placeholderName.private",
"Same as browser.urlbar.placeholderName but for Private Browsing mode. Firefox may use \
a different default search engine in private windows for enhanced privacy, such as DuckDuckGo \
instead of Google.",
),
(
"browser.urlbar.quicksuggest.migrationVersion",
"Tracks the migration version of Firefox Suggest data in your profile. Firefox Suggest \
provides search suggestions as you type in the address bar. This preference records which \
version of the suggestion data format you have, allowing Firefox to migrate data when the \
system updates.",
),
(
"browser.search.serpEventTelemetryCategorization.regionEnabled",
"Controls whether Firefox categorizes search engine results pages (SERPs) for telemetry \
and analysis purposes. When true, Firefox records which search engines you use and categorizes \
your search activity. This helps Mozilla understand search usage patterns.",
),
(
"pdfjs.migrationVersion",
"Stores the migration version for PDF.js (Firefox's built-in PDF viewer). When Firefox \
updates the internal storage format for PDF viewer settings, caches, or form data, this \
number increments to trigger data migration to the new format.",
),
(
"pdfjs.enabledCache.state",
"Caches the enabled state of the PDF.js viewer. When true, PDF.js is active and will \
display PDF files within the browser tab. This preference improves performance by avoiding \
repeated checks of whether the PDF viewer should be enabled.",
),
(
"print_printer",
"Stores the name of the default printer selected in Firefox's print dialog. This \
remembers your printer choice between print sessions. The value 'Mozilla Save to PDF' \
indicates Firefox's built-in PDF printing is selected.",
),
(
"identity.fxaccounts.toolbar.syncSetup.panelAccessed",
"Indicates whether you have accessed the Firefox Sync setup panel from the toolbar. \
When true, you've clicked the Firefox Account button in the toolbar at least once, which \
may affect how Firefox displays sync-related prompts and notifications.",
),
(
"services.sync.engine.addresses.available",
"Indicates whether the Firefox Sync engine for addresses (form autofill addresses) is \
available for your account. When true, your saved addresses will sync across devices signed \
into your Firefox Account.",
),
(
"signon.firefoxRelay.feature",
"Controls the integration with Firefox Relay, Mozilla's email aliasing service that \
helps protect your real email address. The value 'disabled' indicates this feature is turned \
off. Other values may indicate the feature is enabled or set to specific modes.",
),
(
"signon.generation.enabled",
"Controls whether Firefox's password generator feature is enabled. When true, Firefox \
can suggest strong, unique passwords when you create new accounts or change passwords. When \
false, this feature is disabled and you must manually create passwords.",
),
(
"signon.management.page.breach-alerts.enabled",
"Controls whether Firefox shows alerts when your saved passwords have been compromised \
in data breaches. When true, Firefox will notify you in the password manager if any of your \
saved logins appear in known data breaches. When false, these alerts are disabled.",
),
(
"browser.safebrowsing.provider.mozilla.lastupdatetime",
"Unix timestamp of when Firefox last updated Mozilla's Safe Browsing blocklist. Safe \
Browsing protects you from malicious websites, phishing, and dangerous downloads. This \
preference records when the blocklist was last successfully downloaded.",
),
(
"browser.safebrowsing.provider.mozilla.nextupdatetime",
"Unix timestamp scheduled for the next Safe Browsing blocklist update. Firefox \
automatically checks for updates to the malware and phishing site blocklist at regular \
intervals, typically every 30 minutes to several hours depending on the provider.",
),
(
"browser.shell.didSkipDefaultBrowserCheckOnFirstRun",
"Indicates whether Firefox skipped the default browser check on first run. When true, \
Firefox did not prompt you to set it as the default browser during the first launch. This \
may happen in managed environments or if a deployment policy suppresses the prompt.",
),
(
"browser.shell.defaultBrowserCheckCount",
"Counter tracking how many times Firefox has checked if it's the default browser. \
Firefox periodically asks if you want to set it as the default browser if it's not already. \
This number increments with each check and is used to avoid showing the prompt too frequently.",
),
(
"browser.shell.mostRecentDefaultPromptSeen",
"Unix timestamp of when you last saw the prompt to set Firefox as your default browser. \
Firefox uses this to avoid showing the default browser prompt too frequently, ensuring you \
aren't nagged.",
),
(
"browser.policies.applied",
"Indicates whether enterprise policies have been applied to Firefox. When true, Firefox \
is running under policy control (commonly in corporate or managed environments) and certain \
settings may be enforced or restricted by system administrators.",
),
(
"browser.aboutwelcome.didSeeFinalScreen",
"Indicates whether you have completed and dismissed the Firefox welcome/onboarding \
experience. When true, you've reached the end of the welcome tour that appears on first \
launch. Firefox uses this to avoid showing the welcome screens again.",
),
(
"browser.laterrun.enabled",
"Controls Firefox's Later Run feature, which shows optional browser tips and feature \
tours after you've been using Firefox for a while. When true, these delayed prompts may \
appear to highlight useful features. When false, these prompts are disabled.",
),
(
"browser.engagement.fxa-toolbar-menu-button.has-used",
"Tracks whether you have interacted with the Firefox Account toolbar button. When true, \
you've clicked or used the Firefox Account/sync button in the toolbar at least once. This \
may affect how Firefox displays sync-related features and prompts.",
),
(
"distribution.nixos.bookmarksProcessed",
"Indicates whether Firefox has processed NixOS-specific bookmarks. The NixOS Linux \
distribution includes default bookmarks for NixOS documentation and resources. When true, \
these distribution-specific bookmarks have been added to your bookmark library.",
),
(
"distribution.iniFile.exists.appversion",
"Records the Firefox version number when distribution customization files were detected. \
Some Linux distributions and organizations customize Firefox with distribution.ini files. This \
preference tracks which version had these customizations.",
),
(
"distribution.iniFile.exists.value",
"Indicates whether a distribution customization file exists. When true, Firefox found \
a distribution.ini file that customizes settings, bookmarks, or preferences for a specific \
organization or Linux distribution.",
),
(
"storage.vacuum.last.places.sqlite",
"Unix timestamp of the last time Firefox performed vacuum (cleanup and optimization) \
on the places.sqlite database. This database stores your bookmarks and history. Vacuuming \
reclaims space and improves performance as the database grows over time.",
),
(
"storage.vacuum.last.index",
"Index or counter for the last vacuum operation performed on Firefox's storage \
databases. Firefox periodically vacuums its SQLite databases to maintain performance as \
you add bookmarks, history, and other data.",
),
(
"places.database.lastMaintenance",
"Unix timestamp of the last time Firefox performed maintenance on the Places database \
(bookmarks and history). This includes vacuuming, reindexing, and other optimizations to \
keep Firefox responsive as your browsing history grows.",
),
(
"browser.bookmarks.restore_default_bookmarks",
"Controls whether Firefox should restore the default set of bookmarks on next startup. \
When true, Firefox will reset your bookmarks to the default set on the next launch. When \
false (normal), your existing bookmarks are preserved. This is typically set during \
troubleshooting or profile reset operations.",
),
(
"browser.pagethumbnails.storage_version",
"Version number of the page thumbnails storage format. Firefox captures thumbnail \
images of websites you visit for display on the new tab page and in other features. This \
preference tracks the storage format version for migration purposes.",
),
(
"browser.theme.dark.activetab",
"When true, Firefox is using a dark theme variant where the active tab has dark \
styling applied. This preference helps Firefox track which theme variant is active so \
it can properly apply visual updates and theme changes.",
),
(
"browser.proton.toolbar.version",
"Stores the version number of the Proton toolbar design. Firefox's Proton design \
system updated the browser interface with a modern look. This preference tracks which \
iteration of the Proton toolbar design your profile is using.",
),
(
"browser.colorway-builtin-themes-cleanup",
"Internal preference related to Firefox Colorway themes, which were special limited-time \
color themes. This tracks cleanup and migration of colorway theme data after these themes \
were discontinued or moved to the standard theme system.",
),
(
"extensions.activeThemeID",
"Stores the ID of the currently active Firefox theme (e.g., 'default-theme@mozilla.org'). \
This preference tracks which theme is applied, including built-in themes like Light, Dark, \
System, or any installed custom themes.",
),
(
"extensions.colorway-builtin-themes-cleanup",
"Internal migration preference for cleaning up legacy Colorway theme data. When \
Firefox discontinued the Colorway themes (special limited-time color variants), this \
preference tracked removal of old theme data from your profile.",
),
(
"extensions.signatureCheckpoint",
"Internal counter tracking extension signature validation checkpoints. Firefox requires \
extensions to be digitally signed by Mozilla for security. This preference tracks which \
signature validation checks have been completed.",
),
(
"extensions.blocklist.pingCountVersion",
"Counter related to the add-on blocklist ping mechanism. Firefox periodically checks \
if installed extensions are known to be malicious or problematic. This preference tracks \
the version or count of blocklist checks performed.",
),
(
"extensions.getAddons.cache.lastUpdate",
"Unix timestamp of when Firefox last updated the add-ons cache. Firefox caches \
information about available extensions, themes, and plugins from addons.mozilla.org to \
speed up the add-ons manager and provide recommendations.",
),
(
"extensions.getAddons.databaseSchema",
"Version number of the add-ons database schema. This tracks the format version of \
Firefox's internal storage for information about available and installed extensions.",
),
(
"browser.contextual-services.contextId",
"A unique identifier (UUID) for contextual services telemetry and personalization. \
Firefox uses this to track contextual features like Firefox Suggest, Pocket recommendations, \
and other location-based or activity-based services while maintaining user anonymity.",
),
(
"browser.contextual-services.contextId.timestamp-in-seconds",
"Unix timestamp of when the contextual services ID was created. This records when \
Firefox generated the unique identifier used for contextual features, helping to track \
the age and rotation of this identifier.",
),
(
"captchadetection.lastSubmission",
"Unix timestamp of when Firefox last submitted data related to CAPTCHA detection \
and analysis. Firefox may analyze CAPTCHA challenges to improve user experience and \
detect suspicious CAPTCHA behavior.",
),
(
"dom.push.userAgentID",
"A unique identifier (UUID) for Firefox's Push API service. Web applications can use \
the Push API to send you notifications even when the website isn't loaded. This ID uniquely \
identifies your browser to push notification servers.",
),
(
"network.cookie.CHIPS.lastMigrateDatabase",
"Version number of the Cookies Having Independent Partitioned State (CHIPS) database \
migration. CHIPS is a privacy feature that partitions cookies by top-level site to prevent \
cross-site tracking. This tracks which migration version has been applied.",
),
(
"gecko.handlerService.defaultHandlersVersion",
"Version number of the default protocol handlers in Firefox. Protocol handlers allow \
web applications to register as handlers for specific URL schemes (like mailto: links). \
This preference tracks the version of the default handler configuration.",
),
(
"app.update.lastUpdateTime.*",
"A series of preferences storing Unix timestamps of when various automatic update \
and maintenance tasks last ran. These timers control when Firefox checks for add-on \
updates, signature verification, Remote Settings polling, and other periodic background \
tasks. Each timer ensures Firefox doesn't check too frequently, balancing between \
staying current and conserving resources.",
),
(
"media.gmp-manager.buildID",
"Stores the Firefox build ID (version timestamp) that the GMP manager is associated \
with. This helps track which version of Firefox downloaded or updated media plugins, \
allowing Firefox to determine if plugin re-registration or updates are needed after \
browser upgrades.",
),
(
"toolkit.telemetry.previousBuildID",
"Stores the Firefox build ID from the previous browser version. After Firefox updates, \
this preference records what version you were running before. This is used for telemetry \
analysis to understand upgrade patterns and to identify issues that occur specifically \
during upgrades.",
),
(
"extensions.lastAppBuildId",
"Stores the specific Firefox build identifier (version + timestamp) when extensions \
were last validated or updated. This is used to track which browser version was running \
during extension operations, helping to diagnose compatibility issues that arise after \
Firefox updates.",
),
(
"toolkit.profiles.storeID",
"A unique identifier for your Firefox profile's storage location. This ID helps \
Firefox distinguish between different profile directories and is used internally for \
file system operations and profile management.",
),
(
"idle.lastDailyNotification",
"Unix timestamp of the last time Firefox performed daily idle maintenance tasks. \
Firefox runs certain maintenance operations (like database vacuuming, telemetry uploads, \
and data cleanup) when the computer has been idle for a while. This preference tracks \
when these daily tasks were last completed.",
),
(
"browser.tabs.groups.smart.userEnabled",
"Controls whether you have manually enabled smart tab grouping features. When true, \
you've activated Firefox's tab grouping system that organizes tabs based on browsing \
context. When false, smart tab grouping is either disabled or not yet configured.",
),
(
"browser.pageActions.persistedActions",
"JSON-encoded string storing which page actions (bookmark button, screenshot, etc.) \
are pinned to the address bar. This remembers your preferences for which quick-action \
buttons appear in the URL bar, allowing you to customize which page actions are \
immediately accessible.",
),
(
"privacy.sanitize.pending",
"JSON-encoded string tracking pending data sanitization operations that need to \
be executed. When you close Firefox or trigger privacy clearing, this preference may \
hold queued operations to clear specific types of data (history, cookies, cache, etc.) \
to be processed when the browser is in a safe state to do so.",
),
(
"privacy.trackingprotection.consentmanager.skip.pbmode.enabled",
"Controls whether Firefox skips tracking protection consent dialogs in Private \
Browsing mode. When true, Firefox won't show additional consent prompts for tracking \
protection features when in private windows, streamlining the private browsing experience.",
),
(
"browser.startup.homepage_override.mstone",
"Stores the Firefox milestone (major version number) that triggered the homepage \
override behavior. When Firefox updates to a new major version, it may display a special \
'What's New' page once. This preference records which version you last saw, ensuring \
the special homepage only appears once per major version.",
),
(
"browser.startup.homepage_override.buildID",
"Stores the specific Firefox build ID (timestamp-based version) of the last homepage \
override. Similar to mstone but more granular - it tracks the exact build rather than \
just the major version. This helps Firefox decide whether to show update-related pages.",
),
(
"dom.forms.autocomplete.formautofill",
"Controls whether Firefox's form autocomplete feature includes autofill suggestions. \
When true, Firefox will suggest saved information (names, addresses, etc.) when filling \
out forms. This is the master switch that enables or disables the entire form autofill \
suggestion system.",
),
(
"dom.security.https_only_mode_ever_enabled_pbm",
"Records whether HTTPS-Only mode has ever been enabled in Private Browsing mode. \
When true, you've previously activated HTTPS-Only mode while browsing privately. This \
helps Firefox remember your privacy preferences across sessions and may affect default \
behavior in private windows.",
),
(
"trailhead.firstrun.didSeeAboutWelcome",
"Indicates whether you have completed the Firefox Trailhead onboarding experience. \
Trailhead is Firefox's new user experience that guides first-time users through setup \
and feature highlights. When true, you've seen and completed the about:welcome tour.",
),
(
"browser.termsofuse.prefMigrationCheck",
"Internal preference tracking whether you've acknowledged Firefox's updated terms \
of use. When true, Firefox has confirmed you've seen or acknowledged the current terms. \
This may be checked during browser updates to determine if legal terms need to be \
presented again.",
),
(
"extensions.webextensions.uuids",
"JSON-encoded object mapping extension IDs to their unique UUIDs. Every installed \
extension is assigned a UUID for internal identification and security purposes. This \
preference maintains the mapping between extension IDs (like 'webcompat@mozilla.org') \
and their corresponding UUIDs.",
),
(
"services.settings.main.cookie-banner-rules-list.last_check",
"Stores the timestamp of the last check for Firefox's cookie banner handling rules. \
This collection contains rules that automatically detect and handle cookie consent banners \
on websites, clicking 'reject all' buttons or injecting opt-out cookies. The rules are \
site-specific and tell Firefox how to interact with different cookie banner implementations.",
),
(
"services.settings.main.normandy-recipes-capabilities.last_check",
"Records the last check for legacy Normandy recipe capabilities. Normandy was \
Mozilla's previous experiment system (predecessor to Nimbus) that delivered preference \
rollouts, A/B tests, and feature experiments. This collection defined what capabilities \
the Normandy client supported.",
),
(
"services.settings.main.third-party-cookie-blocking-exempt-urls.last_check",
"Timestamp for the last update of the exempt URLs list for third-party cookie blocking. \
Firefox's Enhanced Tracking Protection can block third-party cookies, but some websites \
require certain third-party cookies to function properly. This collection contains URLs \
and domains that are exempt from third-party cookie blocking to prevent website breakage.",
),
(
"services.settings.main.doh-providers.last_check",
"Records the last update check for DNS over HTTPS (DoH) provider configurations. \
This collection contains the list of DoH servers that Firefox can use for encrypted DNS \
resolution, including Cloudflare, NextDNS, and other providers. It includes provider \
settings like endpoint URLs, filtering capabilities, and regional availability.",
),
(
"services.settings.main.webcompat-interventions.last_check",
"Timestamp for the last update of web compatibility interventions. This collection \
contains site-specific fixes and patches that make broken websites work correctly in \
Firefox. These interventions address issues with websites that detect browser features \
incorrectly or rely on non-standard APIs.",
),
(
"services.settings.main.anti-tracking-url-decoration.last_check",
"Records the last check for URL decoration parameters used for tracking protection. \
Some websites add tracking parameters to URLs (like utm_source, fbclid) that allow \
third parties to track users across sites. This collection contains lists of these \
tracking parameters so Firefox can strip them for privacy protection.",
),
(
"services.settings.main.addons-data-leak-blocker-domains.last_check",
"Timestamp for updates to the list of domains where Firefox blocks add-ons to prevent \
data leakage. This security feature prevents extensions from accessing sensitive websites \
like banking sites, payment processors, and government domains where malicious extensions \
could steal credentials or personal data.",
),
(
"services.settings.main.newtab-wallpapers-v2.last_check",
"Records the last update check for Firefox new tab page wallpapers. This collection \
contains metadata about background images (wallpapers) that users can apply to customize \
the new tab page. It includes wallpaper IDs, file locations, and availability information.",
),
(
"services.settings.main.password-recipes.last_check",
"Timestamp for password generation recipe updates. This collection contains rules for \
Firefox's password generator feature, which automatically suggests strong, unique passwords \
when creating new accounts. Recipes define password requirements (length, character types) \
for specific websites based on their password policies.",
),
(
"services.settings.main.search-categorization.last_check",
"Records the last update for search categorization rules. This collection contains \
data that helps Firefox categorize search engines and search results for telemetry and \
analysis purposes, understanding how users interact with different search providers.",
),
(
"services.settings.main.search-config-overrides-v2.last_check",
"Timestamp for search configuration override updates. This collection contains \
region-specific or localized overrides to Firefox's default search engine configuration, \
allowing Mozilla to customize which search engines are available as defaults in different \
countries or regions.",
),
(
"services.settings.main.url-classifier-skip-urls.last_check",
"Records the last update of URLs that should be skipped by Safe Browsing checks. \
Firefox's URL classifier checks websites against malware and phishing blocklists. \
This collection contains URLs known to be safe that can skip these checks to improve \
performance and reduce server load.",
),
(
"services.settings.main.moz-essential-domain-fallbacks.last_check",
"Timestamp for essential domain fallback list updates. This collection contains \
fallback domains for critical Mozilla services. If a primary service endpoint fails, \
Firefox can use these fallback domains to maintain essential functionality like updates, \
Remote Settings sync, and crash reporting.",
),
(
"services.settings.main.websites-with-shared-credential-backends.last_check",
"Records the last update of websites that share credential backend infrastructure. \
This collection identifies websites that use common authentication or payment processing \
systems, which helps Firefox's password manager and autofill features work correctly \
across related sites.",
),
(
"services.settings.main.devtools-compatibility-browsers.last_check",
"Timestamp for updates to the browser compatibility database used by Developer Tools. \
This collection contains information about which web features are supported in different \
browsers and versions, powering the Browser Compatibility tab in DevTools that warns \
developers about features that may not work in other browsers.",
),
(
"services.settings.main.nimbus-secure-experiments.last_check",
"Records the last check for Nimbus secure experiment configurations. Nimbus is \
Mozilla's current experiment system for A/B testing, feature rollouts, and staged \
releases. This collection contains secure experiment definitions that are validated \
and signed before delivery to ensure they haven't been tampered with.",
),
(
"services.settings.main.tracking-protection-lists.last_check",
"Timestamp for tracking protection list updates. This collection contains the \
blocklists used by Firefox's Enhanced Tracking Protection, including lists of known \
tracking scripts, fingerprinting scripts, social media trackers, and cryptominers. \
Firefox downloads these lists regularly to maintain up-to-date protection.",
),
(
"services.settings.main.translations-models.last_check",
"Records the last update check for Firefox Translations models. Firefox's local \
translation feature uses machine learning models to translate web pages without sending \
data to external servers. This collection contains metadata about available translation \
models (language pairs like en→es, fr→de) including file sizes, version numbers, and \
download locations for the Bergamot translation engine models.",
),
(
"services.settings.main.message-groups.last_check",
"Timestamp for Firefox Messaging System message group updates. This collection \
contains configuration for groups of related messages, controlling frequency capping \
(how often messages can show), priority ordering, and targeting rules. It ensures users \
aren't overwhelmed by too many in-product messages.",
),
(
"services.settings.main.partitioning-exempt-urls.last_check",
"Records the last update of URLs exempt from state partitioning. Firefox partitions \
browser state (cookies, cache, storage) by top-level site to prevent cross-site tracking. \
This collection contains sites that are exempt from this partitioning because they \
require third-party context to function (e.g., embedded payment widgets, login systems).",
),
(
"services.settings.main.cfr.last_check",
"Timestamp for Contextual Feature Recommendation (CFR) message updates. CFR is a \
messaging system that suggests Firefox features and extensions at relevant moments, like \
recommending a password manager when you visit a signup page. This collection contains the \
CFR messages that are shown to users.",
),
(
"services.settings.main.url-parser-default-unknown-schemes-interventions.last_check",
"Records the last update for URL parser interventions for unknown schemes. Some \
websites use non-standard or malformed URL schemes that can break or cause unexpected \
behavior. This collection contains site-specific patches to handle these unusual URL \
patterns correctly.",
),
(
"services.settings.main.query-stripping.last_check",
"Timestamp for query parameter stripping list updates. This collection contains \
tracking parameters that Firefox should strip from URLs to enhance privacy. When you \
click a link with tracking parameters (like ?utm_source=email, ?fbclid=123), Firefox \
removes these parameters before navigating to the site, preventing the destination site \
from tracking how you arrived there.",
),
(
"services.settings.main.search-config-v2.last_check",
"Records the last update for the search engine configuration. This collection \
contains comprehensive data about search engines available in Firefox, including their \
names, URLs, parameter formats, icon URLs, and regional availability. It's the master \
list that determines which search engines appear in Firefox's search options.",
),
(
"services.settings.main.nimbus-desktop-experiments.last_check",
"Timestamp for desktop-specific Nimbus experiment updates. This is the main collection \
for Firefox desktop experiments, containing A/B test configurations, feature rollouts, \
and staged feature releases. It defines which users see which experiment variants based \
on targeting criteria.",
),
(
"services.settings.main.urlbar-persisted-search-terms.last_check",
"Records the last update for URL bar search term persistence configuration. This \
collection contains settings for whether and how Firefox remembers search terms in the \
address bar, allowing users to see and reuse their previous searches.",
),
(
"services.settings.main.search-config-icons.last_check",
"Timestamp for search engine icon updates. This collection contains the icon images \
and metadata for search engines that appear in Firefox's search selector and address bar. \
Icons are periodically updated to reflect current search engine branding.",
),
(
"services.settings.main.devtools-devices.last_check",
"Records the last update for the Developer Tools device list. This collection contains \
information about mobile devices, tablets, and other viewports available in DevTools' \
Responsive Design Mode. It includes device names, screen sizes, user agent strings, and \
touch capabilities for testing responsive designs.",
),
(
"services.settings.main.url-classifier-exceptions.last_check",
"Timestamp for Safe Browsing exception list updates. This collection contains URLs \
and domains that should be exempt from Safe Browsing checks. Sites may be on this list \
if they were incorrectly flagged as malicious or if they are known-safe internal services \
that trigger false positives.",
),
(
"services.settings.main.sites-classification.last_check",
"Records the last update for website classification data. This collection contains \
categories and classifications for websites, which Firefox may use for various purposes \
including telemetry analysis, feature targeting, and understanding user interaction \
patterns with different types of sites.",
),
(
"services.settings.main.translations-wasm.last_check",
"Timestamp for Firefox Translations WebAssembly module updates. The translation \
feature uses a WASM-compiled version of the Bergamot translation engine. This collection \
contains metadata about the WASM binaries, including version numbers, file sizes, and \
download locations for the translation runtime environment.",
),
(
"services.settings.main.bounce-tracking-protection-exceptions.last_check",
"Records the last update for bounce tracking protection exception list. Bounce \
trackers redirect users through intermediate sites to track their behavior. Firefox's \
bounce tracking protection blocks this technique, but this collection contains sites \
that are exempt because they use redirects for legitimate purposes (like login flows).",
),
(
"services.settings.main.hijack-blocklists.last_check",
"Timestamp for hijack blocklist updates. This collection contains domains and \
patterns associated with browser hijacking attempts, such as sites that try to modify \
browser settings, hijack the new tab page, or inject unwanted search engines. Firefox \
blocks these to protect user control of the browser.",
),
(
"services.settings.main.remote-permissions.last_check",
"Records the last update for remotely configured permission policies. This collection \
contains permission settings that can be updated without a browser update, such as which \
websites can access sensitive APIs or how certain permission prompts should behave \
in specific contexts.",
),
(
"services.settings.main.fingerprinting-protection-overrides.last_check",
"Timestamp for fingerprinting protection override list updates. Firefox's \
fingerprinting protection blocks techniques that uniquely identify your browser. This \
collection contains site-specific overrides for when stricter protection would break \
legitimate functionality.",
),
(
"services.settings.main.password-rules.last_check",
"Records the last update for password generation rules. This collection contains \
detailed password requirements for websites, such as minimum length, required character \
types, and forbidden characters. Firefox's password generator uses these rules to create \
passwords that will be accepted by each website's signup form.",
),
(
"services.settings.main.search-default-override-allowlist.last_check",
"Timestamp for search engine override allowlist updates. This collection contains \
search engines that are permitted to override the default search engine in specific \
regions or contexts. It ensures that only approved search engines can be set as defaults \
through certain installation or configuration methods.",
),
(
"services.settings.main.addons-manager-settings.last_check",
"Records the last update for add-ons manager configuration. This collection contains \
settings and policies for Firefox's extension management system, including blocklist \
data, recommended extensions, and administrative policies for enterprise deployments.",
),
(
"services.settings.main.doh-config.last_check",
"Timestamp for DNS over HTTPS configuration updates. This collection contains \
DoH deployment settings including which providers to use in different regions, automatic \
enablement rules, and network-based heuristics for when to enable or disable DoH based \
on the detected network environment.",
),
(
"services.settings.main.search-telemetry-v2.last_check",
"Records the last update for search telemetry configuration. This collection contains \
rules for categorizing and analyzing search engine usage patterns. It helps Mozilla \
understand which search engines users prefer, how search behavior varies by region, and \
how search features are being used.",
),
(
"services.settings.main.top-sites.last_check",
"Timestamp for Top Sites configuration updates. This collection contains default \
sites and configuration for Firefox's new tab page Top Sites section, which shows \
frequently-visited websites for quick access. It includes sponsored site configurations \
and regional site recommendations.",
),
(
"services.settings.main.language-dictionaries.last_check",
"Records the last update for spell-check dictionary metadata. This collection contains \
information about available spell-check dictionaries for different languages, including \
download locations, version numbers, and file sizes. Firefox uses this to provide spell \
checking in text fields and text areas.",
),
(
"app.update.lastUpdateTime.browser-cleanup-thumbnails",
"Timestamp of the last time Firefox ran the browser thumbnail cleanup task. Firefox \
captures page thumbnails for the new tab page and session restore. This maintenance task \
removes old or unused thumbnails to free up disk space and keep the thumbnail cache \
manageable.",
),
(
"app.update.lastUpdateTime.recipe-client-addon-run",
"Timestamp of the last execution of the Normandy recipe client add-on. Normandy \
was Mozilla's legacy system for delivering experiments, preference rollouts, and feature \
configurations. This timer controlled when Firefox checked for and applied new recipes. \
(Note: Normandy has been replaced by the Nimbus system.)",
),
(
"app.update.lastUpdateTime.xpi-signature-verification",
"Timestamp of the last time Firefox verified extension signatures. All Firefox \
extensions must be digitally signed by Mozilla to ensure they haven't been tampered \
with. This periodic task re-validates installed extensions to maintain security and \
detect any compromised or modified add-ons.",
),
(
"app.update.lastUpdateTime.services-settings-poll-changes",
"Timestamp of the last time Firefox polled for Remote Settings changes. This timer \
controls how often Firefox checks Mozilla's servers for updates to Remote Settings \
collections, ensuring blocklists, experiment configurations, and other remotely-delivered \
data stay current.",
),
(
"app.update.lastUpdateTime.region-update-timer",
"Timestamp of the last time Firefox updated its detected home region. Firefox \
determines your geographic region based on your IP address to provide localized search \
engines, region-specific content, and compliance with local regulations. This timer \
controls how often this region detection is updated.",
),
(
"app.update.lastUpdateTime.rs-experiment-loader-timer",
"Timestamp of the last time Firefox loaded experiment configurations from Remote \
Settings. This timer controls when Firefox checks for new Nimbus experiments and feature \
rollouts, enabling staged rollouts and A/B tests that can be deployed without requiring \
a browser update.",
),
(
"app.update.lastUpdateTime.suggest-ingest",
"Timestamp of the last time Firefox ingested Firefox Suggest data. Firefox Suggest \
provides search suggestions, sponsored shortcuts, and quick results as you type in the \
address bar. This timer controls how often this suggestion data is refreshed from \
Mozilla's servers.",
),
(
"app.update.lastUpdateTime.addon-background-update-timer",
"Timestamp of the last time Firefox checked for add-on updates in the background. \
This timer controls how frequently Firefox automatically checks for updates to installed \
extensions and themes, ensuring you have the latest versions with security fixes and \
new features.",
),
(
"services.settings.security-state.onecrl.last_check",
"Timestamp for the last update of the OneCRL (One CRL Revocation List) certificate \
blocklist. This collection contains intermediate certificates that have been revoked \
or are known to be compromised. Firefox blocks websites using these certificates to \
protect against man-in-the-middle attacks and fraudulent websites.",
),
(
"services.settings.blocklists.addons-bloomfilters.last_check",
"Timestamp for the last update of the add-on blocklist bloom filters. This collection \
contains compact data structures for efficiently checking if extensions are on the \
blocklist. Bloom filters allow Firefox to quickly determine if an extension ID is known \
to be malicious or problematic without downloading the full blocklist.",
),
(
"services.settings.security-state.intermediates.last_check",
"Timestamp for the last update of intermediate certificate data. This collection \
contains intermediate certificates that are trusted for TLS/SSL connections. Firefox \
uses this to properly validate certificate chains and establish secure HTTPS connections.",
),
(
"services.settings.security-state.cert-revocations.last_check",
"Timestamp for the last update of the certificate revocation list. This collection \
contains information about certificates that have been revoked before their expiration \
date. Firefox checks this list to prevent connections to sites using compromised or \
fraudulent certificates.",
),
(
"services.settings.blocklists.gfx.last_check",
"Timestamp for the last update of the graphics driver blocklist. This collection \
contains graphics drivers and hardware configurations known to cause stability or \
security issues. Firefox blocks or restricts certain GPU features (like hardware acceleration \
or WebGL) on these problematic configurations to prevent crashes and vulnerabilities.",
),
])
})
.get(key)
.copied()
}