diff --git a/Marlin/planner.cpp b/Marlin/planner.cpp
index ffed52c04..1d6ab073f 100644
--- a/Marlin/planner.cpp
+++ b/Marlin/planner.cpp
@@ -1354,7 +1354,7 @@ void Planner::_buffer_steps(const int32_t (&target)[XYZE], float fr_mm_s, const
 } // _buffer_steps()
 
 /**
- * Planner::_buffer_line
+ * Planner::buffer_segment
  *
  * Add a new linear movement to the buffer in axis units.
  *
@@ -1364,7 +1364,7 @@ void Planner::_buffer_steps(const int32_t (&target)[XYZE], float fr_mm_s, const
  *  fr_mm_s   - (target) speed of the move
  *  extruder  - target extruder
  */
-void Planner::_buffer_line(const float &a, const float &b, const float &c, const float &e, const float &fr_mm_s, const uint8_t extruder) {
+void Planner::buffer_segment(const float &a, const float &b, const float &c, const float &e, const float &fr_mm_s, const uint8_t extruder) {
   // When changing extruders recalculate steps corresponding to the E position
   #if ENABLED(DISTINCT_E_FACTORS)
     if (last_extruder != extruder && axis_steps_per_mm[E_AXIS_N] != axis_steps_per_mm[E_AXIS + last_extruder]) {
@@ -1383,7 +1383,7 @@ void Planner::_buffer_line(const float &a, const float &b, const float &c, const
   };
 
   /* <-- add a slash to enable
-    SERIAL_ECHOPAIR("  _buffer_line FR:", fr_mm_s);
+    SERIAL_ECHOPAIR("  buffer_segment FR:", fr_mm_s);
     #if IS_KINEMATIC
       SERIAL_ECHOPAIR(" A:", a);
       SERIAL_ECHOPAIR(" (", position[A_AXIS]);
@@ -1430,7 +1430,7 @@ void Planner::_buffer_line(const float &a, const float &b, const float &c, const
 
   stepper.wake_up();
 
-} // _buffer_line()
+} // buffer_segment()
 
 /**
  * Directly set the planner XYZ position (and stepper positions)
diff --git a/Marlin/planner.h b/Marlin/planner.h
index 0378e1375..24e5cbee8 100644
--- a/Marlin/planner.h
+++ b/Marlin/planner.h
@@ -142,7 +142,7 @@ class Planner {
      *            head!=tail : blocks are in the buffer
      *   head==(tail-1)%size : the buffer is full
      *
-     *  Writer of head is Planner::_buffer_line().
+     *  Writer of head is Planner::buffer_segment().
      *  Reader of tail is Stepper::isr(). Always consider tail busy / read-only
      */
     static block_t block_buffer[BLOCK_BUFFER_SIZE];
@@ -375,7 +375,7 @@ class Planner {
     static void _buffer_steps(const int32_t (&target)[XYZE], float fr_mm_s, const uint8_t extruder);
 
     /**
-     * Planner::_buffer_line
+     * Planner::buffer_segment
      *
      * Add a new linear movement to the buffer in axis units.
      *
@@ -385,7 +385,7 @@ class Planner {
      *  fr_mm_s   - (target) speed of the move
      *  extruder  - target extruder
      */
-    static void _buffer_line(const float &a, const float &b, const float &c, const float &e, const float &fr_mm_s, const uint8_t extruder);
+    static void buffer_segment(const float &a, const float &b, const float &c, const float &e, const float &fr_mm_s, const uint8_t extruder);
 
     static void _set_position_mm(const float &a, const float &b, const float &c, const float &e);
 
@@ -405,7 +405,7 @@ class Planner {
       #if PLANNER_LEVELING && IS_CARTESIAN
         apply_leveling(rx, ry, rz);
       #endif
-      _buffer_line(rx, ry, rz, e, fr_mm_s, extruder);
+      buffer_segment(rx, ry, rz, e, fr_mm_s, extruder);
     }
 
     /**
@@ -426,9 +426,9 @@ class Planner {
       #endif
       #if IS_KINEMATIC
         inverse_kinematics(raw);
-        _buffer_line(delta[A_AXIS], delta[B_AXIS], delta[C_AXIS], cart[E_AXIS], fr_mm_s, extruder);
+        buffer_segment(delta[A_AXIS], delta[B_AXIS], delta[C_AXIS], cart[E_AXIS], fr_mm_s, extruder);
       #else
-        _buffer_line(raw[X_AXIS], raw[Y_AXIS], raw[Z_AXIS], cart[E_AXIS], fr_mm_s, extruder);
+        buffer_segment(raw[X_AXIS], raw[Y_AXIS], raw[Z_AXIS], cart[E_AXIS], fr_mm_s, extruder);
       #endif
     }
 
diff --git a/Marlin/ubl_motion.cpp b/Marlin/ubl_motion.cpp
index a8fa65eec..bb455ab9c 100644
--- a/Marlin/ubl_motion.cpp
+++ b/Marlin/ubl_motion.cpp
@@ -134,7 +134,7 @@
         // Note: There is no Z Correction in this case. We are off the grid and don't know what
         // a reasonable correction would be.
 
-        planner._buffer_line(end[X_AXIS], end[Y_AXIS], end[Z_AXIS], end[E_AXIS], feed_rate, extruder);
+        planner.buffer_segment(end[X_AXIS], end[Y_AXIS], end[Z_AXIS], end[E_AXIS], feed_rate, extruder);
         set_current_from_destination();
 
         if (g26_debug_flag)
@@ -178,7 +178,7 @@
        */
       if (isnan(z0)) z0 = 0.0;
 
-      planner._buffer_line(end[X_AXIS], end[Y_AXIS], end[Z_AXIS] + z0, end[E_AXIS], feed_rate, extruder);
+      planner.buffer_segment(end[X_AXIS], end[Y_AXIS], end[Z_AXIS] + z0, end[E_AXIS], feed_rate, extruder);
 
       if (g26_debug_flag)
         debug_current_and_destination(PSTR("FINAL_MOVE in ubl.line_to_destination()"));
@@ -269,7 +269,7 @@
          * Without this check, it is possible for the algorithm to generate a zero length move in the case
          * where the line is heading down and it is starting right on a Mesh Line boundary. For how often that
          * happens, it might be best to remove the check and always 'schedule' the move because
-         * the planner._buffer_line() routine will filter it if that happens.
+         * the planner.buffer_segment() routine will filter it if that happens.
          */
         if (ry != start[Y_AXIS]) {
           if (!inf_normalized_flag) {
@@ -282,7 +282,7 @@
             z_position = end[Z_AXIS];
           }
 
-          planner._buffer_line(rx, ry, z_position + z0, e_position, feed_rate, extruder);
+          planner.buffer_segment(rx, ry, z_position + z0, e_position, feed_rate, extruder);
         } //else printf("FIRST MOVE PRUNED  ");
       }
 
@@ -333,7 +333,7 @@
          * Without this check, it is possible for the algorithm to generate a zero length move in the case
          * where the line is heading left and it is starting right on a Mesh Line boundary. For how often
          * that happens, it might be best to remove the check and always 'schedule' the move because
-         * the planner._buffer_line() routine will filter it if that happens.
+         * the planner.buffer_segment() routine will filter it if that happens.
          */
         if (rx != start[X_AXIS]) {
           if (!inf_normalized_flag) {
@@ -346,7 +346,7 @@
             z_position = end[Z_AXIS];
           }
 
-          planner._buffer_line(rx, ry, z_position + z0, e_position, feed_rate, extruder);
+          planner.buffer_segment(rx, ry, z_position + z0, e_position, feed_rate, extruder);
         } //else printf("FIRST MOVE PRUNED  ");
       }
 
@@ -408,7 +408,7 @@
           e_position = end[E_AXIS];
           z_position = end[Z_AXIS];
         }
-        planner._buffer_line(rx, next_mesh_line_y, z_position + z0, e_position, feed_rate, extruder);
+        planner.buffer_segment(rx, next_mesh_line_y, z_position + z0, e_position, feed_rate, extruder);
         current_yi += dyi;
         yi_cnt--;
       }
@@ -436,7 +436,7 @@
           z_position = end[Z_AXIS];
         }
 
-        planner._buffer_line(next_mesh_line_x, ry, z_position + z0, e_position, feed_rate, extruder);
+        planner.buffer_segment(next_mesh_line_x, ry, z_position + z0, e_position, feed_rate, extruder);
         current_xi += dxi;
         xi_cnt--;
       }
@@ -468,14 +468,14 @@
     #endif
 
     // We don't want additional apply_leveling() performed by regular buffer_line or buffer_line_kinematic,
-    // so we call _buffer_line directly here.  Per-segmented leveling and kinematics performed first.
+    // so we call buffer_segment directly here.  Per-segmented leveling and kinematics performed first.
 
     inline void _O2 ubl_buffer_segment_raw(const float raw[XYZE], const float &fr) {
 
       #if ENABLED(DELTA)  // apply delta inverse_kinematics
 
         DELTA_RAW_IK();
-        planner._buffer_line(delta[A_AXIS], delta[B_AXIS], delta[C_AXIS], raw[E_AXIS], fr, active_extruder);
+        planner.buffer_segment(delta[A_AXIS], delta[B_AXIS], delta[C_AXIS], raw[E_AXIS], fr, active_extruder);
 
       #elif IS_SCARA  // apply scara inverse_kinematics (should be changed to save raw->logical->raw)
 
@@ -488,11 +488,11 @@
         scara_oldB = delta[B_AXIS];
         float s_feedrate = max(adiff, bdiff) * scara_feed_factor;
 
-        planner._buffer_line(delta[A_AXIS], delta[B_AXIS], delta[C_AXIS], raw[E_AXIS], s_feedrate, active_extruder);
+        planner.buffer_segment(delta[A_AXIS], delta[B_AXIS], delta[C_AXIS], raw[E_AXIS], s_feedrate, active_extruder);
 
       #else // CARTESIAN
 
-        planner._buffer_line(raw[X_AXIS], raw[Y_AXIS], raw[Z_AXIS], raw[E_AXIS], fr, active_extruder);
+        planner.buffer_segment(raw[X_AXIS], raw[Y_AXIS], raw[Z_AXIS], raw[E_AXIS], fr, active_extruder);
 
       #endif
     }
@@ -511,7 +511,7 @@
 
     /**
      * Prepare a segmented linear move for DELTA/SCARA/CARTESIAN with UBL and FADE semantics.
-     * This calls planner._buffer_line multiple times for small incremental moves.
+     * This calls planner.buffer_segment multiple times for small incremental moves.
      * Returns true if did NOT move, false if moved (requires current_position update).
      */