Simply install the Log Comment addon and the functionality will be enabled.
It takes any plain text you enter and makes an entry in the log.
The text entry field in the comment popup is automatically pre-filled with the current page path because the page will often be something you want to include in the comment. If you don't want the page, just cut that part of the text.
Comments are converted into plain text. When saving to the log, any html will be escaped to show the actual <tags>.
The tool is shown to users who have both of these permissions set
For those who want to customize the comment popup dialogue style, two configuration values can optionally be set in application/config/generated_overrides/jl_log_comment.php to define colors.
Colours can be in any CSS acceptable format.
When not explicitly set, these configuration values default to:
[code]
[ 'format'=>[ 'text_color'=> '#101010', 'background_color' => '#fff79d', ] ];
[/code]