diff --git a/docs/graphics-protocol.rst b/docs/graphics-protocol.rst
index ceb7a79d2..8bd94116e 100644
--- a/docs/graphics-protocol.rst
+++ b/docs/graphics-protocol.rst
@@ -347,7 +347,7 @@ Value of `t`          Meaning
 ``s``                 A *shared memory object*, which on POSIX systems is a
                       `POSIX shared memory object <https://pubs.opengroup.org/onlinepubs/9699919799/functions/shm_open.html>`_
                       and on Windows is a
-                      `Named shared memory object <https://docs.microsoft.com/en-us/windows/win32/memory/creating-named-shared-memory>`_. On POSIX shm names **must** start with a :file:`/` and be at most ``NAME_MAX`` characters none of which are slashes.
+                      `Named shared memory object <https://docs.microsoft.com/en-us/windows/win32/memory/creating-named-shared-memory>`_. On POSIX shm names **must** start with a :file:`/` and have no other :file:`/` characters and must be no longer than the maximum SHM name size supported by the OS
                       The terminal emulator must read the data from the memory
                       object and then unlink and close it on POSIX and just
                       close it on Windows.