diff --git a/local/recipes/tui/tlc/source/src/viewer/mod.rs b/local/recipes/tui/tlc/source/src/viewer/mod.rs
index fa274f3cd4..2c98e51a9e 100644
--- a/local/recipes/tui/tlc/source/src/viewer/mod.rs
+++ b/local/recipes/tui/tlc/source/src/viewer/mod.rs
@@ -109,6 +109,9 @@ pub struct Viewer {
     /// True when the cursor navigates the ASCII text column in
     /// hex mode (MC hexview_in_text). Toggled by Tab.
     pub hexview_in_text: bool,
+    /// Whether nroff backspace-overstrike formatting is active.
+    /// Toggled by F9 when the menubar is not active (MC F9).
+    pub nroff_enabled: bool,
     /// Active modal prompt at the bottom of the viewer (`None` =
     /// no prompt open). Drives the prompt's title and Enter
     /// handler.
@@ -187,6 +190,7 @@ impl Viewer {
             last_search_forward: true,
             ruler: false,
             hexview_in_text: false,
+            nroff_enabled: false,
             prompt: None,
             prompt_input: String::new(),
             loading: size >= crate::viewer::source::INLINE_THRESHOLD,
@@ -232,6 +236,7 @@ impl Viewer {
             last_search_forward: true,
             ruler: false,
             hexview_in_text: false,
+            nroff_enabled: false,
             prompt: None,
             prompt_input: String::new(),
             loading: size >= crate::viewer::source::INLINE_THRESHOLD,
@@ -789,11 +794,25 @@ impl Viewer {
         }
 
         if chunks[3].height > 0 {
-            let labels: [(&str, &str); 10] = [
-                ("1", "Help"), ("2", "Wrap"), ("3", ""), ("4", "Hex"),
-                ("5", ""), ("6", ""), ("7", "Search"), ("8", "Magic"),
-                ("9", ""), ("10", "Quit"),
-            ];
+            let labels: [(&str, &str); 10] = if self.mode == ViewMode::Hex {
+                [
+                    ("1", "Help"), ("2", "Edit"), ("3", "Quit"), ("4", "Ascii"),
+                    ("5", "Goto"), ("6", "Save"), ("7", "HxSrch"), ("8", "Raw"),
+                    ("9", ""), ("10", "Quit"),
+                ]
+            } else if self.mode == ViewMode::HexEdit {
+                [
+                    ("1", "Help"), ("2", "View"), ("3", "Quit"), ("4", "Ascii"),
+                    ("5", "Goto"), ("6", "Save"), ("7", "HxSrch"), ("8", "Raw"),
+                    ("9", ""), ("10", "Quit"),
+                ]
+            } else {
+                [
+                    ("1", "Help"), ("2", "Wrap"), ("3", ""), ("4", "Hex"),
+                    ("5", ""), ("6", ""), ("7", "Search"), ("8", "Magic"),
+                    ("9", "Nroff"), ("10", "Quit"),
+                ]
+            };
             crate::widget::buttonbar::render_buttonbar(frame, chunks[3], theme, &labels);
         }
 
@@ -881,8 +900,18 @@ impl Viewer {
         if key == Key::f(10) || key == Key::ctrl('q') {
             return true;
         }
-        // F9 toggles the menubar.
+        // F9 — toggle NroffMode (MC CK_NroffMode parity).
+        // Shift-F9 opens the viewer menubar.
         if key == Key::f(9) {
+            self.nroff_enabled = !self.nroff_enabled;
+            return true;
+        }
+        // Shift-F9 opens the menubar.
+        let shift_f9 = Key {
+            code: Key::f(9).code,
+            mods: crate::key::Modifiers::SHIFT,
+        };
+        if key == shift_f9 {
             if self.menubar.is_some() {
                 self.menubar = None;
             } else {