A change log entry starts with a header line that contains the current date, your name (taken from the variable add-log-full-name), and your email address (taken from the variable add-log-mailing-address). Aside from these header lines, every line in the change log starts with a space or a tab. The bulk of the entry consists of items, each of which starts with a line starting with whitespace and a star. Here are two entries, both dated in May 1993, with two items and one item respectively.

1993-05-25  Richard Stallman  <rms@@gnu.org>

        * man.el: Rename symbols 'man-*' to 'Man-*'.
        (manual-entry): Make prompt string clearer.

        * simple.el (blink-matching-paren-distance):
        Change default to 12,000.

1993-05-24  Richard Stallman  <rms@@gnu.org>

        * vc.el (minor-mode-map-alist): Don't use it if it's void.
        (vc-cancel-version): Doc fix.

One entry can describe several changes; each change should have its own item, or its own line in an item. Normally there should be a blank line between items. When items are related (parts of the same change, in different places), group them by leaving no blank line between them. You should put a copyright notice and permission notice at the end of the change log file. Here is an example:

Copyright 1997--1998, 2025 Free Software Foundation, Inc.
Copying and distribution of this file, with or without modification, are
permitted provided the copyright notice and this notice are preserved.

@noindent Of course, you should substitute the proper years and copyright holder.