--- a/browser/browser/preferences/preferences.ftl
+++ b/browser/browser/preferences/preferences.ftl
@@ -334,20 +334,16 @@ check-user-spelling =
     .accesskey = t
 
 ## General Section - Files and Applications
 
 files-and-applications-title = Files and Applications
 
 download-header = Downloads
 
-download-save-to =
-    .label = Save files to
-    .accesskey = v
-
 download-save-where = Save files to
     .accesskey = v
 
 download-choose-folder =
     .label =
         { PLATFORM() ->
             [macos] Choose…
            *[other] Browse…
@@ -1412,13 +1408,8 @@ httpsonly-radio-enabled-pbm =
 httpsonly-radio-disabled =
     .label = Don’t enable HTTPS-Only Mode
 
 ## The following strings are used in the Download section of settings
 
 desktop-folder-name = Desktop
 downloads-folder-name = Downloads
 choose-download-folder-title = Choose Download Folder:
-
-# Variables:
-#   $service-name (String) - Name of a cloud storage provider like Dropbox, Google Drive, etc...
-save-files-to-cloud-storage =
-    .label = Save files to { $service-name }

deleted file mode 100644
--- a/browser/browser/upgradeDialog.ftl
+++ /dev/null
@@ -1,50 +0,0 @@
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-### Strings for the upgrade dialog that can be displayed on major version change.
-
-## Start screen
-
-# This title can be explicitly wrapped to control which words are on which line.
-upgrade-dialog-start-title = Life in color
-upgrade-dialog-start-subtitle = Vibrant new colorways. Available for a limited time.
-upgrade-dialog-start-primary-button = Explore colorways
-upgrade-dialog-start-secondary-button = Not now
-
-## Colorway screen
-
-# This title can be explicitly wrapped to control which words are on which line.
-upgrade-dialog-colorway-title = Pick your palette
-# This is shown to users with a custom home page, so they can switch to default.
-upgrade-dialog-colorway-home-checkbox = Switch to Firefox Home with themed background
-upgrade-dialog-colorway-primary-button = Save colorway
-upgrade-dialog-colorway-secondary-button = Keep previous theme
-upgrade-dialog-colorway-theme-tooltip =
-    .title = Explore default themes
-# $colorwayName (String) - Name of colorway, e.g., Abstract, Cheers
-upgrade-dialog-colorway-colorway-tooltip =
-    .title = Explore { $colorwayName } colorways
-upgrade-dialog-colorway-default-theme = Default
-# "Auto" is short for "Automatic"
-upgrade-dialog-colorway-theme-auto = Auto
-    .title = Follow the operating system theme for buttons, menus, and windows
-upgrade-dialog-theme-light = Light
-    .title = Use a light theme for buttons, menus, and windows
-upgrade-dialog-theme-dark = Dark
-    .title = Use a dark theme for buttons, menus, and windows
-upgrade-dialog-colorway-variation-soft = Soft
-    .title = Use this colorway
-upgrade-dialog-colorway-variation-balanced = Balanced
-    .title = Use this colorway
-# "Bold" is used in the sense of bravery or courage, not in the sense of
-# emphasized text.
-upgrade-dialog-colorway-variation-bold = Bold
-    .title = Use this colorway
-
-## Thank you screen
-
-# This title can be explicitly wrapped to control which words are on which line.
-upgrade-dialog-thankyou-title = Thank you for choosing us
-upgrade-dialog-thankyou-subtitle = { -brand-short-name } is an independent browser backed by a non-profit. Together, we’re making the web safer, healthier, and more private.
-upgrade-dialog-thankyou-primary-button = Start browsing

--- a/browser/chrome/browser/browser.properties
+++ b/browser/chrome/browser/browser.properties
@@ -852,21 +852,16 @@ emeNotifications.drmContentDisabled.mess
 emeNotifications.drmContentDisabled.button.label = Enable DRM
 emeNotifications.drmContentDisabled.button.accesskey = E
 
 # LOCALIZATION NOTE(emeNotifications.drmContentCDMInstalling.message): NB: inserted via innerHTML, so please don't use <, > or & in this string. %S is brandShortName
 emeNotifications.drmContentCDMInstalling.message = %S is installing components needed to play the audio or video on this page. Please try again later.
 
 emeNotifications.unknownDRMSoftware = Unknown
 
-# LOCALIZATION NOTE  - %S is brandShortName
-flashHang.message = %S changed some Adobe Flash settings to improve performance.
-flashHang.helpButton.label = Learn More…
-flashHang.helpButton.accesskey = L
-
 # LOCALIZATION NOTE (customizeMode.tabTitle): %S is brandShortName
 customizeMode.tabTitle = Customize %S
 
 e10s.accessibilityNotice.acceptButton.label = OK
 e10s.accessibilityNotice.acceptButton.accesskey = O
 
 # LOCALIZATION NOTE (e10s.accessibilityNotice.jawsMessage): %S is brandShortName
 e10s.accessibilityNotice.jawsMessage = Display of tab content is disabled due to incompatibility between %S and your accessibility software. Please update your screen reader or switch to Firefox Extended Support Release.

--- a/devtools/client/debugger.properties
+++ b/devtools/client/debugger.properties
@@ -337,24 +337,16 @@ breakpointMenuItem.disableAllAtLine.acce
 breakpointMenuItem.enableAllAtLine.label=Enable breakpoints on line
 breakpointMenuItem.enableAllAtLine.accesskey=L
 breakpointMenuItem.removeAllAtLine.label=Remove breakpoints on line
 breakpointMenuItem.removeAllAtLine.accesskey=X
 
 # LOCALIZATION NOTE (breakpoints.header): Breakpoints right sidebar pane header.
 breakpoints.header=Breakpoints
 
-# LOCALIZATION NOTE (breakpoints.enable): The text that may appear as a tooltip
-# when hovering over the 'disable breakpoints' switch button in right sidebar
-breakpoints.enable=Enable breakpoints
-
-# LOCALIZATION NOTE (breakpoints.disable): The text that may appear as a tooltip
-# when hovering over the 'disable breakpoints' switch button in right sidebar
-breakpoints.disable=Disable breakpoints
-
 # LOCALIZATION NOTE (breakpoints.removeBreakpointTooltip): The tooltip that is displayed
 # for remove breakpoint button in right sidebar
 breakpoints.removeBreakpointTooltip=Remove breakpoint
 
 # LOCALIZATION NOTE (callStack.header): Call Stack right sidebar pane header.
 callStack.header=Call stack
 
 # LOCALIZATION NOTE (callStack.notPaused): Call Stack right sidebar pane

deleted file mode 100644
--- a/devtools/client/sourceeditor.dtd
+++ /dev/null
@@ -1,17 +0,0 @@
-<!-- This Source Code Form is subject to the terms of the Mozilla Public
-   - License, v. 2.0. If a copy of the MPL was not distributed with this
-   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
-
-<!-- LOCALIZATION NOTE : FILE This file contains the Source Editor component
-  - strings. The source editor component is used within the Style Editor. -->
-
-<!-- LOCALIZATION NOTE : FILE Do not translate commandkeys -->
-
-<!-- LOCALIZATION NOTE : FILE The correct localization of this file might be to
-  - keep it in English, or another language commonly spoken among web developers.
-  - You want to make that choice consistent across the developer tools.
-  - A good criteria is the language in which you'd find the best
-  - documentation on web development on the web. -->
-
-<!ENTITY gotoLineCmd.label         "Jump to Line…">
-<!ENTITY gotoLineCmd.accesskey     "J">

deleted file mode 100644
--- a/devtools/client/storage.dtd
+++ /dev/null
@@ -1,17 +0,0 @@
-<!-- This Source Code Form is subject to the terms of the Mozilla Public
-   - License, v. 2.0. If a copy of the MPL was not distributed with this
-   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
-
-<!-- LOCALIZATION NOTE : This file contains the Storage Inspector strings. -->
-
-<!-- LOCALIZATION NOTE : Placeholder for the searchbox that allows you to filter the table items. -->
-<!ENTITY searchBox.placeholder         "Filter Items">
-
-<!-- LOCALIZATION NOTE : Label of popup menu action to delete all storage items. -->
-<!ENTITY storage.popupMenu.deleteAllLabel "Delete All">
-
-<!-- LOCALIZATION NOTE : Label of popup menu action to delete all session cookies. -->
-<!ENTITY storage.popupMenu.deleteAllSessionCookiesLabel "Delete All Session Cookies">
-
-<!-- LOCALIZATION NOTE : Label of popup menu action to copy a storage item. -->
-<!ENTITY storage.popupMenu.copyLabel "Copy">

deleted file mode 100644
--- a/devtools/client/storage.properties
+++ /dev/null
@@ -1,102 +0,0 @@
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-# LOCALIZATION NOTE These strings are used inside the Storage Editor tool.
-# LOCALIZATION NOTE The correct localization of this file might be to keep it
-# in English, or another language commonly spoken among web developers.
-# You want to make that choice consistent across the developer tools.
-# A good criteria is the language in which you'd find the best documentation
-# on web development on the web.
-
-# LOCALIZATION NOTE (storage.filter.key):
-# Key shortcut used to focus the filter box on top of the data view
-storage.filter.key=CmdOrCtrl+F
-
-# LOCALIZATION NOTE (tree.labels.*):
-# These strings are the labels for Storage type groups present in the Storage
-# Tree, like cookies, local storage etc.
-tree.labels.cookies=Cookies
-tree.labels.localStorage=Local Storage
-tree.labels.sessionStorage=Session Storage
-tree.labels.indexedDB=Indexed DB
-tree.labels.Cache=Cache Storage
-tree.labels.extensionStorage=Extension Storage
-
-# LOCALIZATION NOTE (table.headers.*.*):
-# These strings are the header names of the columns in the Storage Table for
-# each type of storage available through the Storage Tree to the side.
-table.headers.cookies.name=Name
-table.headers.cookies.value=Value
-table.headers.cookies.expires2=Expires / Max-Age
-table.headers.cookies.size=Size
-table.headers.cookies.lastAccessed2=Last Accessed
-table.headers.cookies.creationTime2=Created
-
-table.headers.Cache.status=Status
-
-table.headers.indexedDB.uniqueKey=Unique key
-table.headers.indexedDB.name=Key
-table.headers.indexedDB.db=Database Name
-table.headers.indexedDB.storage=Storage
-table.headers.indexedDB.objectStore=Object Store Name
-table.headers.indexedDB.value=Value
-table.headers.indexedDB.origin=Origin
-table.headers.indexedDB.version=Version
-table.headers.indexedDB.objectStores=Object Stores
-table.headers.indexedDB.keyPath2=Key Path
-table.headers.indexedDB.autoIncrement=Auto Increment
-table.headers.indexedDB.indexes=Indexes
-
-table.headers.extensionStorage.area=Storage Area
-
-# LOCALIZATION NOTE (label.expires.session):
-# This string is displayed in the expires column when the cookie is Session
-# Cookie
-label.expires.session=Session
-
-# LOCALIZATION NOTE (storage.search.placeholder):
-# This is the placeholder text in the sidebar search box
-storage.search.placeholder=Filter values
-
-# LOCALIZATION NOTE (storage.data.label):
-# This is the heading displayed over the item value in the sidebar
-storage.data.label=Data
-
-# LOCALIZATION NOTE (storage.parsedValue.label):
-# This is the heading displayed over the item parsed value in the sidebar
-storage.parsedValue.label=Parsed Value
-
-# LOCALIZATION NOTE (storage.popupMenu.deleteLabel):
-# Label of popup menu action to delete storage item.
-storage.popupMenu.deleteLabel=Delete “%S”
-
-# LOCALIZATION NOTE (storage.popupMenu.addItemLabel):
-# Label of popup menu action to add an item.
-storage.popupMenu.addItemLabel=Add Item
-
-# LOCALIZATION NOTE (storage.popupMenu.refreshItemLabel):
-# Label of popup menu action to refresh an item.
-storage.popupMenu.refreshItemLabel=Refresh Items
-
-# LOCALIZATION NOTE (storage.popupMenu.deleteAllFromLabel):
-# Label of popup menu action to delete all storage items.
-storage.popupMenu.deleteAllFromLabel=Delete All From “%S”
-
-# LOCALIZATION NOTE (storage.idb.deleteBlocked):
-# Warning notification when IndexedDB database could not be deleted immediately.
-storage.idb.deleteBlocked=Database “%S” will be deleted after all connections are closed.
-
-# LOCALIZATION NOTE (storage.idb.deleteError):
-# Error notification when IndexedDB database could not be deleted.
-storage.idb.deleteError=Database “%S” could not be deleted.
-
-# LOCALIZATION NOTE (storage.expandPane):
-# This is the tooltip for the button that collapses the right panel in the
-# storage UI when the panel is closed.
-storage.expandPane=Expand Pane
-
-# LOCALIZATION NOTE (storage.collapsePane):
-# This is the tooltip for the button that collapses the right panel in the
-# storage UI when the panel is open.
-storage.collapsePane=Collapse Pane

--- a/netwerk/necko.properties
+++ b/netwerk/necko.properties
@@ -45,18 +45,16 @@ CookiePartitionedForeign2=Partitioned cookie or storage access was provided to “%1$S” because it is loaded in the third-party context and dynamic state partitioning is enabled.
 CookieAllowedForOriginByStorageAccessAPI=Storage access granted for origin “%2$S” on “%1$S”.
 # LOCALIZATION NOTE (CookieAllowedForOriginByHeuristic): %2$S and %1$S are URLs.
 CookieAllowedForOriginByHeuristic=Storage access automatically granted for origin “%2$S” on “%1$S”.
 # LOCALIZATION NOTE (CookieAllowedForFpiByHeuristic): %2$S and %1$S are URLs.
 CookieAllowedForFpiByHeuristic=Storage access automatically granted for First-Party isolation “%2$S” on “%1$S”.
 
 # LOCALIZATION NOTE(CookieRejectedNonRequiresSecure2): %1$S is the cookie name. Do not localize "SameSite=None" and "secure".
 CookieRejectedNonRequiresSecure2=Cookie “%1$S” rejected because it has the “SameSite=None” attribute but is missing the “secure” attribute.
-# LOCALIZATION NOTE(CookieRejectedNonRequiresSecureForBeta2): %1$S is the cookie name. %2$S is a URL. Do not localize "SameSite", "SameSite=None" and "secure".
-CookieRejectedNonRequiresSecureForBeta2=Cookie “%1$S” will be soon rejected because it has the “SameSite” attribute set to “None” or an invalid value, without the “secure” attribute. To know more about the “SameSite“ attribute, read %2$S
 # LOCALIZATION NOTE(CookieRejectedNonRequiresSecureForBeta3): %1$S is the cookie name. %2$S is a URL. Do not localize "SameSite", "SameSite=None" and "secure".
 CookieRejectedNonRequiresSecureForBeta3=Cookie “%1$S” will be soon rejected because it has the “SameSite” attribute set to “None” without the “secure” attribute. To know more about the “SameSite“ attribute, read %2$S
 # LOCALIZATION NOTE(CookieLaxForced2): %1$S is the cookie name. Do not localize "SameSite", "Lax" and "SameSite=Lax".
 CookieLaxForced2=Cookie “%1$S” has “SameSite” policy set to “Lax” because it is missing a “SameSite” attribute, and “SameSite=Lax” is the default value for this attribute.
 # LOCALIZATION NOTE(CookieLaxForcedForBeta2): %1$S is the cookie name. %2$S is a URL. Do not localize "SameSite", "Lax" and "SameSite=Lax", "SameSite=None".
 CookieLaxForcedForBeta2=Cookie “%1$S” does not have a proper “SameSite” attribute value. Soon, cookies without the “SameSite” attribute or with an invalid value will be treated as “Lax”. This means that the cookie will no longer be sent in third-party contexts. If your application depends on this cookie being available in such contexts, please add the “SameSite=None“ attribute to it. To know more about the “SameSite“ attribute, read %2$S
 # LOCALIZATION NOTE(CookieSameSiteValueInvalid2): %1$S is cookie name. Do not localize "SameSite", "Lax", "Strict" and "None"
 CookieSameSiteValueInvalid2=Invalid “SameSite“ value for cookie “%1$S”. The supported values are: “Lax“, “Strict“, “None“.

deleted file mode 100644
--- a/toolkit/chrome/global/videocontrols.dtd
+++ /dev/null
@@ -1,48 +0,0 @@
-<!-- This Source Code Form is subject to the terms of the Mozilla Public
-   - License, v. 2.0. If a copy of the MPL was not distributed with this
-   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
-
-<!ENTITY % brandDTD
-    SYSTEM "chrome://branding/locale/brand.dtd">
-  %brandDTD;
-
-<!ENTITY playButton.playLabel "Play">
-<!ENTITY playButton.pauseLabel "Pause">
-<!ENTITY muteButton.muteLabel "Mute">
-<!ENTITY muteButton.unmuteLabel "Unmute">
-<!ENTITY fullscreenButton.enterfullscreenlabel "Full Screen">
-<!ENTITY fullscreenButton.exitfullscreenlabel "Exit Full Screen">
-<!ENTITY castingButton.castingLabel "Cast to Screen">
-<!ENTITY closedCaption.off "Off">
-
-<!-- LOCALIZATION NOTE (pictureInPicture.label): This string is used as part of
-the Picture-in-Picture video toggle button when the mouse is hovering it. -->
-<!ENTITY pictureInPicture.label "Picture-in-Picture">
-
-<!-- LOCALIZATION NOTE (pictureInPictureToggle.label): This string is used as the
-label for a variation of the Picture-in-Picture video toggle button when the mouse is
-hovering over the video. -->
-<!ENTITY pictureInPictureToggle.label "Watch in Picture-in-Picture">
-<!-- LOCALIZATION NOTE (pictureInPictureExplainer): This string is used as part of
-a variation of the Picture-in-Picture video toggle button. When using this variation,
-this string appears below the toggle when the mouse hovers the toggle. -->
-<!ENTITY pictureInPictureExplainer "Play videos in the foreground while you do other things in &brandShortName;">
-
-<!ENTITY error.aborted "Video loading stopped.">
-<!ENTITY error.network "Video playback aborted due to a network error.">
-<!ENTITY error.decode "Video can’t be played because the file is corrupt.">
-<!ENTITY error.srcNotSupported "Video format or MIME type is not supported.">
-<!ENTITY error.noSource2 "No video with supported format and MIME type found.">
-<!ENTITY error.generic "Video playback aborted due to an unknown error.">
-
-<!ENTITY status.pictureInPicture "This video is playing in Picture-in-Picture mode.">
-
-<!-- LOCALIZATION NOTE (positionAndDuration.nameFormat): the #1 string is the current
-media position, and the #2 string is the total duration. For example, when at
-the 5 minute mark in a 6 hour long video, #1 would be "5:00" and #2 would be
-"6:00:00", result string would be "5:00 / 6:00:00".
-Note that #2 is not always available. For example, when at the 5 minute mark in an
-unknown duration video, #1 would be "5:00" and the string which is surrounded by
-<span> would be deleted, result string would be "5:00".
--->
-<!ENTITY positionAndDuration.nameFormat "#1<span> / #2</span>">

--- a/toolkit/toolkit/about/aboutProcesses.ftl
+++ b/toolkit/toolkit/about/aboutProcesses.ftl
@@ -46,17 +46,16 @@ about-processes-privilegedmozilla-proces
 about-processes-gmp-plugin-process = Gecko Media Plugins ({ $pid })
 about-processes-gpu-process = GPU ({ $pid })
 about-processes-vr-process = VR ({ $pid })
 about-processes-rdd-process = Data Decoder ({ $pid })
 about-processes-socket-process = Network ({ $pid })
 about-processes-remote-sandbox-broker-process = Remote Sandbox Broker ({ $pid })
 about-processes-fork-server-process = Fork Server ({ $pid })
 about-processes-preallocated-process = Preallocated ({ $pid })
-
 about-processes-utility-process = Utility ({ $pid })
 
 # Unknown process names
 # Variables:
 #    $pid (String) The process id of this process, assigned by the OS.
 #    $type (String) The raw type for this process.
 about-processes-unknown-process = Other: { $type } ({ $pid })
 

--- a/toolkit/toolkit/about/aboutSupport.ftl
+++ b/toolkit/toolkit/about/aboutSupport.ftl
@@ -347,17 +347,16 @@ multi-process-windows = { $remoteWindows
 # $fissionWindows (integer) - Number of remote windows
 # $totalWindows (integer) - Number of total windows
 fission-windows = { $fissionWindows }/{ $totalWindows }
 fission-status-experiment-control = Disabled by experiment
 fission-status-experiment-treatment = Enabled by experiment
 fission-status-disabled-by-e10s-env = Disabled by environment
 fission-status-enabled-by-env = Enabled by environment
 fission-status-disabled-by-env = Disabled by environment
-fission-status-disabled-by-safe-mode = Disabled by safe mode
 fission-status-enabled-by-default = Enabled by default
 fission-status-disabled-by-default = Disabled by default
 fission-status-enabled-by-user-pref = Enabled by user
 fission-status-disabled-by-user-pref = Disabled by user
 fission-status-disabled-by-e10s-other = E10s disabled
 fission-status-enabled-by-rollout = Enabled by phased rollout
 
 async-pan-zoom = Asynchronous Pan/Zoom