--text follows this line-- [O] for out (exited) and [I] for in (entered) for Emacs windows focus events are sent to buffers for the functions registered to the focus-change-function events, AFAICT, and the frame-focus-state maps to those codes (t -> [I], nil -> [O]). In order to reproduce this, one needs to simply do C-u, wait for it to appear in the mini buffer, and then switch to another frame. The code "[ O-" will appear in the mini buffer. Upon returning focus to the frame, the "[ O-" will be replaced by [ I-" in the minibuffer. This would not be such a problem, if it were not for these codes being thrown into the _main_ buffer when in LFE major mode ("[O [I [O [I [[O [I [O]]] I [O [I]]]]]]") and switching back and forth among different Emacs frames and different system app windows. I communicated to Robert Virding (the creator and maintainer of LFE mode), but it was unclear to me if he saw this message. Regardless, I told him that I would seek assistance from the larger Emacs community on this issue, since it too occurs in the minibuffer regardless of major modes. It can be replicated for example in at least both List Interaction ElDoc mode and Text mode. This behavior of event codes being sent to the minibuffer once C-u is typed and frames lose focus was first detected in macOS' Terminal app when connecting to a Raspberry Pi OS instance of Emacs over ssh, then a local instance of Emacs running in the Terminal app on macOs, and then finally also replicated on the Windows Console app. The behavior does not occur when running Emacs in graphical mode. In GNU Emacs 28.1 (build 1, x86_64-apple-darwin15.6.0, NS appkit-1404.47 Version 10.11.6 (Build 15G22010)) of 2022-05-11 built on builder10-11.lan System Description: Mac OS X 10.11.6 Configured using: 'configure --with-ns '--enable-locallisppath=/Library/Application Support/Emacs/${version}/site-lisp:/Library/Application Support/Emacs/site-lisp' --with-modules CFLAGS=-DNSTextAlignmentRight=NSRightTextAlignment' Configured features: ACL GMP GNUTLS JSON LIBXML2 MODULES NOTIFY KQUEUE NS PDUMPER THREADS TOOLKIT_SCROLL_BARS ZLIB Important settings: value of $LANG: en_US.UTF-8 locale-coding-system: utf-8-unix Major mode: Fundamental Minor modes in effect: tooltip-mode: t global-eldoc-mode: t show-paren-mode: t electric-indent-mode: t mouse-wheel-mode: t tool-bar-mode: t menu-bar-mode: t file-name-shadow-mode: t global-font-lock-mode: t blink-cursor-mode: t auto-composition-mode: t auto-encryption-mode: t auto-compression-mode: t buffer-read-only: t line-number-mode: t indent-tabs-mode: t transient-mark-mode: t Load-path shadows: None found. Features: (shadow sort mail-extr emacsbug message rmc puny dired dired-loaddefs rfc822 mml mml-sec epa derived epg rfc6068 epg-config gnus-util rmail rmail-loaddefs auth-source cl-seq eieio eieio-core cl-macs eieio-loaddefs password-cache json map text-property-search time-date subr-x seq mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader cl-loaddefs cl-lib sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils term/xterm xterm byte-opt gv bytecomp byte-compile cconv iso-transl tooltip eldoc paren electric uniquify ediff-hook vc-hooks lisp-float-type elisp-mode mwheel term/ns-win ns-win ucs-normalize mule-util term/common-win tool-bar dnd fontset image regexp-opt fringe tabulated-list replace newcomment text-mode lisp-mode prog-mode register page tab-bar menu-bar rfn-eshadow isearch easymenu timer select scroll-bar mouse jit-lock font-lock syntax font-core term/tty-colors frame minibuffer cl-generic cham georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean japanese eucjp-ms cp51932 hebrew greek romanian slovak czech european ethiopic indian cyrillic chinese composite emoji-zwj charscript charprop case-table epa-hook jka-cmpr-hook help simple abbrev obarray cl-preloaded nadvice button loaddefs faces cus-face macroexp files window text-properties overlay sha1 md5 base64 format env code-pages mule custom widget hashtable-print-readable backquote threads kqueue cocoa ns multi-tty make-network-process emacs) Memory information: ((conses 16 55267 10759) (symbols 48 6667 1) (strings 32 18265 1947) (string-bytes 1 597801) (vectors 16 11475) (vector-slots 8 136249 7693) (floats 8 24 245) (intervals 56 251 0) (buffers 992 11))