diff --git a/admin/git-bisect-start b/admin/git-bisect-start
index 18dca4bef8b..cf0c8cde410 100755
--- a/admin/git-bisect-start
+++ b/admin/git-bisect-start
@@ -1,31 +1,40 @@
 #!/bin/bash
 
-# Start a git bisection, and prune the branches that are the result of
-# merging external trees into the Emacs repository.
+### Start a git bisection, and prune the branches that are the result of
+### merging external trees into the Emacs repository.
 
-# Copyright (C) 2022 Free Software Foundation, Inc.
+## Copyright (C) 2022 Free Software Foundation, Inc.
 
-# This file is part of GNU Emacs.
+## This file is part of GNU Emacs.
 
-# GNU Emacs is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
+## GNU Emacs is free software: you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation, either version 3 of the License, or
+## (at your option) any later version.
 
-# GNU Emacs is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
+## GNU Emacs is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU General Public License for more details.
 
-# You should have received a copy of the GNU General Public License
-# along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+## You should have received a copy of the GNU General Public License
+## along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+
+### Commentary:
+
+## Marking the last commits of external tree merges as "good" ensures
+## that all the commits between the external tree root and the merge
+## (excluding the merge-commit itself) are regarded as "good", so "git
+## bisect" will never descend into these branches, which only have the
+## files of the external tree, and in which Emacs can therefore not be
+## built.  The last commit is the parent of the merge commit in the
+## external tree, that is, the parent of the merge commit that is not
+## on master.
+
+### Code:
 
 git bisect start
 
 # Prune commits 1e5b753bf4..806734c1b1 introduced by 0186faf2a1 (Eglot
 # merge on Oct 20 2022)
-# The following tells Git that all the commits between Eglot's root
-# and its merge to master (excluding the merge-commit itself) are
-# regarded as "good", so "git bisect" will never descend into the
-# Eglot's branch, because that branch doesn't have all the files.
 git bisect good 806734c1b1f433de43d59d9a5e3a1e89d64315f6