This event is signalled by html_secedit_button() in inc/html.php.
An array with the following values:
secid: The ID (incrementing integer) of the objecttarget: The object type to edit (e.g., section for normal sections)range: The byte range of the object as string in the form \d+-\d*name (optional): The name of the edit section. If this was not specified by the renderer (normal sections) or your syntax plugin, you have to provide a name in your handler, otherwise the edit button will not show up.