From fba67322d6ac80907bfdb095da50d5047066bb1e Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Fri, 6 Mar 2026 10:32:45 +0530
Subject: [PATCH] Some docs

---
 docs/dnd-protocol.rst | 13 +++++++++++++
 kitty/dnd.c           |  3 ++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/docs/dnd-protocol.rst b/docs/dnd-protocol.rst
index 6798cbdcb..70459e6c1 100644
--- a/docs/dnd-protocol.rst
+++ b/docs/dnd-protocol.rst
@@ -51,6 +51,18 @@ code::
 
 to inform the terminal that it no longer wants drops.
 
+Whenever the user drags something over the window, the terminal will send an
+escape code of the form::
+
+    OSC _dnd_code ; t=m:x=x:y=y:X=X:Y=Y ; optional MIME list ST
+
+Here, ``x, y`` identify the cell over which the drag is currently present.
+The ``(0, 0)`` cell is at top left of the screen. ``X and Y`` are the pixel
+offsets from the top-left. The optional list of MIMES is a space separated
+list of MIME types that are available for dropping. To avoid overhead, the
+terminal should only send this list for the first move event and subsequently
+only if the list changes.
+
 Metadata reference
 ---------------------------
 
@@ -63,6 +75,7 @@ Key      Value                 Default    Description
 ``t``    Single character.     ``a``      The type of drag and drop event.
          ``(a, A,                         ``a`` - start accepting drops
          )``                              ``A`` - stop accepting drops
+                                          ``m`` - a drop move event
 
 ``m``    Chunking indicator    ``0``      ``0`` or ``i``
 
diff --git a/kitty/dnd.c b/kitty/dnd.c
index 93fbd97e3..4e3e2b06f 100644
--- a/kitty/dnd.c
+++ b/kitty/dnd.c
@@ -7,6 +7,7 @@
 
 #include "dnd.h"
 #include "base64.h"
+#include "control-codes.h"
 
 static void
 drop_free_offered_mimes(Window *w) {
@@ -124,7 +125,7 @@ drop_move_on_child(Window *w, const char** mimes, size_t num_mimes) {
     // we simply drop this event if there is too much data being written to the child
     if (w->drop.pending.count) return;
     char buf[128];
-    int header_size = snprintf(buf, sizeof(buf), "\x1b]%d;i=%u:t=m:x=%u:y=%u:X=%d:Y=%d", w->drop.client_id,
+    int header_size = snprintf(buf, sizeof(buf), "\x1b]%d;i=%u:t=m:x=%u:y=%u:X=%d:Y=%d", DND_CODE, w->drop.client_id,
             w->mouse_pos.cell_x, w->mouse_pos.cell_y, (int)w->mouse_pos.global_x, (int)w->mouse_pos.global_y);
     if (mimes_total_size) {
         mimes_total_size += 1;