runtime(doc): clarify behaviour of 'title' and 'iconstring'

Document that some terminals sets the 'icon' as window title. Just like
'title' would.  Which can be confusing and need to be documented for
both options.

closes: #20553

Signed-off-by: Celelibi <celelibi@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index 7339133c6db4ddc31e1d41a8ad0589b57bcd4854..7b3713b0d465100205b1e2c21b9f0af7578e2e83 100644 (file)
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -1,4 +1,4 @@
-*options.txt*  For Vim version 9.2.  Last change: 2026 Jun 23
+*options.txt*  For Vim version 9.2.  Last change: 2026 Jul 03
 
 
                  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -4948,6 +4948,9 @@ A jump table for the options with a short description can be found at |Q_op|.
        restored if possible |X11|.  See |X11-icon| for changing the icon on
        X11.
        For MS-Windows the icon can be changed, see |windows-icon|.
+       NOTE: Some terminals treat the icon text as an alias for the window
+       title.  On those, setting the icon text may also change the terminal
+       window title; see 'title'.
 
                                                *'iconstring'*
 'iconstring'           string  (default "")
@@ -9635,6 +9638,9 @@ A jump table for the options with a short description can be found at |Q_op|.
        then the WINDOWID environment variable should be inherited and the
        title of the window should change back to what it should be after
        exiting Vim.
+       NOTE: Some terminals treat the icon text as an alias for the window
+       title (see 'icon').  On those, the interaction between 'title' and
+       'icon' depend on the specific behavior of the terminal.
 
                                                                *'titlelen'*
 'titlelen'             number  (default 85)