diff --git a/flake.lock b/flake.lock
index 290045b63..457cd5257 100644
--- a/flake.lock
+++ b/flake.lock
@@ -138,11 +138,11 @@
         "nixpkgs": "nixpkgs_3"
       },
       "locked": {
-        "lastModified": 1756197489,
-        "narHash": "sha256-S16rPaBH1TnMbDyL5NlGSJcYd7wPlOEWTStdBDL7BHw=",
+        "lastModified": 1763347184,
+        "narHash": "sha256-6QH8hpCYJxifvyHEYg+Da0BotUn03BwLIvYo3JAxuqQ=",
         "owner": "oxalica",
         "repo": "rust-overlay",
-        "rev": "8ec04f46f1edeeed3f870da62191745b93975da7",
+        "rev": "08895cce80433978d5bfd668efa41c5e24578cbd",
         "type": "github"
       },
       "original": {
diff --git a/scripts/rust-toolchain b/scripts/rust-toolchain
index b7844a6ff..8d3947429 100644
--- a/scripts/rust-toolchain
+++ b/scripts/rust-toolchain
@@ -1 +1 @@
-1.86.0
+1.91.1
diff --git a/src/main/res/values/strings.xml b/src/main/res/values/strings.xml
index 907d34e76..0aa23c82a 100644
--- a/src/main/res/values/strings.xml
+++ b/src/main/res/values/strings.xml
@@ -81,7 +81,9 @@
     <string name="always_load_remote_images">Always Load Remote Images</string>
     <string name="once">Once</string>
     <string name="show_warning">Show Warning</string>
+    <!-- deprecated, UI must not offer an option to show the password -->
     <string name="show_password">Show Password</string>
+    <!-- deprecated, UI must not offer an option to show the password -->
     <string name="hide_password">Hide Password</string>
     <string name="not_now">Not now</string>
     <string name="never">Never</string>
@@ -814,9 +816,10 @@
     <string name="pref_imap_folder_warn_disable_defaults">If you change this option, make sure, your server and your other clients are configured accordingly.\n\nOtherwise things may not work at all.</string>
     <!-- deprecated -->
     <string name="pref_watch_sent_folder">Watch Sent Folder</string>
-    <string name="pref_send_copy_to_self">Multi-device Mode</string>
-    <string name="pref_send_copy_to_self_explain">Send background messages for device synchronization. Automatically enabled on adding a second device</string>
-    <string name="pref_multidevice_change_warn">Multi-device Mode must be enabled when using the same profile on multiple devices. Only disable this setting if you have removed this profile from all your other devices.\n\nDisabling multi-device mode while using the profile on multiple devices will result in missed messages and other problems.</string>
+    <!-- No need to be literal here, you can also use "Use Multiple Devices", "Support Multiple Devices" or other fitting terms. However, it should fit to the wording or your language at https://delta.chat/help  -->
+    <string name="pref_send_copy_to_self">Multi-Device Mode</string>
+    <string name="pref_send_copy_to_self_explain">Synchronize your messages with your other devices. Automatically enabled on adding a second device</string>
+    <string name="pref_multidevice_change_warn">Multi-Device Mode must be enabled when using the same profile on multiple devices. Only disable this setting if you have removed this profile from all your other devices.\n\nDisabling Multi-Device Mode while using the profile on multiple devices will result in missed messages and other problems.</string>
     <string name="pref_auto_folder_moves">Move automatically to DeltaChat Folder</string>
     <string name="pref_auto_folder_moves_explain">Chat conversations are moved to avoid cluttering the Inbox</string>
     <string name="pref_only_fetch_mvbox_title">Only Fetch from DeltaChat Folder</string>