diff --git a/runtime/doc/builtin.txt b/runtime/doc/builtin.txt
index b9d0719..717f13a 100644
--- a/runtime/doc/builtin.txt
+++ b/runtime/doc/builtin.txt
@@ -1,4 +1,4 @@
-*builtin.txt*	For Vim version 9.1.  Last change: 2025 May 09
+*builtin.txt*	For Vim version 9.1.  Last change: 2025 May 14
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -4730,6 +4730,8 @@
 		If not over a window, e.g. when in the command line, then only
 		"screenrow" and "screencol" are valid, the others are zero.
 
+		When on the |tabpanel|, "wincol" value is zero.
+
 		When on the status line below a window or the vertical
 		separator right of a window, the "line" and "column" values
 		are zero.