From 7d3870b7f88ab4c09b35920258b60b0cdcd269dd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kacper=20Michaj=C5=82ow?= <kasper93@gmail.com>
Date: Mon, 14 Jul 2025 20:23:19 +0200
Subject: [PATCH] DOCS/man/options: add a note about MAINPRESUB and gpu-next

---
 DOCS/man/options.rst | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/DOCS/man/options.rst b/DOCS/man/options.rst
index 1ab0b34d87..b5b891ad2e 100644
--- a/DOCS/man/options.rst
+++ b/DOCS/man/options.rst
@@ -6498,6 +6498,14 @@ them.
         The image, after conversion to RGB, but before
         ``--blend-subtitles=video`` is applied.
 
+        .. note::
+            With ``--vo=gpu``, ``MAIN`` and ``MAINPRESUB`` are separate shader
+            stages, this allows rendering overlays directly onto the pre-scaled
+            video stage. ``--vo=gpu-next`` does not support this feature,
+            and as such, the ``MAINPRESUB`` shader stage does not exist.
+            It is still valid to refer to this name in shaders, but it is
+            handled identically to ``MAIN``.
+
     MAIN (resizable)
         The main image, after conversion to RGB but before upscaling.